This TechBook describes how implementation of EMC VPLEX leads to a higher level of availability. It also introduces VPLEX High Availability and the VPLEX Witness.
Gestion de consommation d'eau et d’ÉlectricitéAhmed EL ATARI
L’objectif de ce mini projet proposé est de valider nos acquis dans le module « Algorithmique
et Programmation » à travers le développement d’une application console en langage C/C++ .
Note :
Je m'excuse pour les erreurs de frappe .
Soutenance Elhadj Bah | Diplôme d'ingénieur de conception en Informatique | E...Elhadj Mamadou Aliou BAH
Présentation de soutenance pour l'obtention du diplôme d'ingénieur de conception en informatique: conception et réalisation d'un jeu vidéo de combat africain multiplateforme (Android et iOS)
Exemple d'une mise en situation par un projet virtuel #SAP au CESI École Supérieure de l’Alternance de Toulouse. Déploiement SAP pour l’entreprise Resins4You avec un focus sur la partie Transport par Claude Collange, Armand DARAEI, séverin menga et pryavahiny kichenaradja
Gestion de consommation d'eau et d’ÉlectricitéAhmed EL ATARI
L’objectif de ce mini projet proposé est de valider nos acquis dans le module « Algorithmique
et Programmation » à travers le développement d’une application console en langage C/C++ .
Note :
Je m'excuse pour les erreurs de frappe .
Soutenance Elhadj Bah | Diplôme d'ingénieur de conception en Informatique | E...Elhadj Mamadou Aliou BAH
Présentation de soutenance pour l'obtention du diplôme d'ingénieur de conception en informatique: conception et réalisation d'un jeu vidéo de combat africain multiplateforme (Android et iOS)
Exemple d'une mise en situation par un projet virtuel #SAP au CESI École Supérieure de l’Alternance de Toulouse. Déploiement SAP pour l’entreprise Resins4You avec un focus sur la partie Transport par Claude Collange, Armand DARAEI, séverin menga et pryavahiny kichenaradja
Depuis des siècles, l'homme utilise l'énergie du vent pour faire avancer des bateaux, moudre du grain ou pomper de l'eau. Cette source d'énergie nous sert maintenant à produire de l'électricité.
Cahier de cours de génie mécanique pour les élèves de la quatrième année sciences techniques. Ce cahier est proposé par Mr Mtaallah Mohamed, Enseignant de génie mécanique au lycée secondaire AbdelAziz Khouja à Kélibia, Tunisie.
Rapprot de satge supervision de résau par EyesOfNetwokAbdessamad IDRISSI
ce document est un rapport de stage qui explique l'installation et la configuration d'un logiciel open source de supervision de réseaux il s'agit bien de EyesOfNetwork.
Il contient la configuration de serveur DHCP, DNS et WEB sous linux et la supervision de ces derniers par EON, ainsi que des machines Windows et linux.
la compréhension de la complexité d'un système mécatronique ne peut être envisagée que si les acteurs ont des connaissances de base communes en mécanique , électronique et informatique
Networking for Storage Virtualization and EMC RecoverPoint TechBook EMC
This EMC Engineering TechBook provides a high-level overview of using block storage virtualization solutions, such as EMC VPLEX and Invista, as well as RecoverPoint replication protection. Basic information on interswitch link hops, along with examples showing hop counts in four different fabric configurations, are included.
White Paper: Using VPLEX Metro with VMware High Availability and Fault Tolera...EMC
This white paper discusses using best of breed technologies from VMware and EMC to create federated continuous availability solutions. The following topics are reviewed: choosing between federated FT or federated HA, design considerations and constraints, and operational best practice.
Depuis des siècles, l'homme utilise l'énergie du vent pour faire avancer des bateaux, moudre du grain ou pomper de l'eau. Cette source d'énergie nous sert maintenant à produire de l'électricité.
Cahier de cours de génie mécanique pour les élèves de la quatrième année sciences techniques. Ce cahier est proposé par Mr Mtaallah Mohamed, Enseignant de génie mécanique au lycée secondaire AbdelAziz Khouja à Kélibia, Tunisie.
Rapprot de satge supervision de résau par EyesOfNetwokAbdessamad IDRISSI
ce document est un rapport de stage qui explique l'installation et la configuration d'un logiciel open source de supervision de réseaux il s'agit bien de EyesOfNetwork.
Il contient la configuration de serveur DHCP, DNS et WEB sous linux et la supervision de ces derniers par EON, ainsi que des machines Windows et linux.
la compréhension de la complexité d'un système mécatronique ne peut être envisagée que si les acteurs ont des connaissances de base communes en mécanique , électronique et informatique
Networking for Storage Virtualization and EMC RecoverPoint TechBook EMC
This EMC Engineering TechBook provides a high-level overview of using block storage virtualization solutions, such as EMC VPLEX and Invista, as well as RecoverPoint replication protection. Basic information on interswitch link hops, along with examples showing hop counts in four different fabric configurations, are included.
White Paper: Using VPLEX Metro with VMware High Availability and Fault Tolera...EMC
This white paper discusses using best of breed technologies from VMware and EMC to create federated continuous availability solutions. The following topics are reviewed: choosing between federated FT or federated HA, design considerations and constraints, and operational best practice.
BELLY DANCES AND INDIAN CLASSICAL DANCES - EMBEDDING EROTICISM, SPIRITUALITY...Dr. Raju M. Mathew
The striking similarity of Belly Dances - Arab, Russian and Brazilian and the Indian Classical Dances such as Bharathanatiyam, Carnatic Dance, Kathak, Kuchipudi, Mohiniyattom and Odissi has been discussed mainly with the help of pictures. They are embedded with Eroticism, Spirituality and Aesthetics. This work may be useful for the dancers, dancing students, dance critics and above all lovers of dances.
Learn about IBM PowerVM Virtualization Introduction and Configuration. PowerVM is a combination of hardware, firmware, and software that provides CPU, network, and disk virtualization.This publication is also designed to be an introduction guide for system administrators, providing instructions for tasks like Configuration and creation of partitions and resources on the HMC,Installation and configuration of the Virtual I/O Server, creation and installation of virtualized partitions. For more information on Power Systems, visit http://ibm.co/Lx6hfc.
Visit http://on.fb.me/LT4gdu to 'Like' the official Facebook page of IBM India Smarter Computing.
TechBook: IMS on z/OS Using EMC Symmetrix Storage SystemsEMC
This EMC Engineering TechBook provides a general description of EMC products that can be used for IMS administration on z/OS. Using EMC products to manage IMS environments can reduce database and storage management administration, reduce CPU resource consumption, and reduce the time required to clone, backup, or recover IMS systems.
This EMC Engineering TechBook provides insight and understanding of some options available for managing your data center connectivity, including information on some new software management tools developed to bridge the gap in the I/O consolidation environment.
Learn about the configuration of IBM PowerVC. IBM PowerVC is built on OpenStack that controls large pools of server, storage, and networking resources throughout a data center. IBM Power Virtualization Center provides security services that support a secure environment. Installation requires just 20 minutes to get a virtual machine up and running. For more information on Power Systems, visit http://ibm.co/Lx6hfc.
Visit http://on.fb.me/LT4gdu to 'Like' the official Facebook page of IBM India Smarter Computing.
Learn about IBM PowerVM Best Practices.This IBM Redbooks publication provides best practices for planning, installing, maintaining, and monitoring the IBM PowerVM Enterprise Edition virtualization features on IBM POWER7 processor technology-based servers.
For more information on Power Systems, visit http://ibm.co/Lx6hfc.
Visit http://bit.ly/KWh5Dx to 'Follow' the official Twitter handle of IBM India Smarter Computing.
AIX 5L Version 5.3 introduces many new features, including NFS Version 4 and Advanced Accounting, and exploits the advanced capabilities of POWER5 equipped severs, such as Virtual SCSI, Virtual Ethernet SMT, Micro-Partitioning, and others. This IBM Redbook focuses on the differences introduced in AIX 5L Version 5.3 when compared to AIX 5L Version 5.2. For more information on Power Systems, visit http://ibm.co/Lx6hfc.
Visit the official Scribd Channel of IBM India Smarter Computing at http://bit.ly/VwO86R to get access to more documents.
TechBook: DB2 for z/OS Using EMC Symmetrix Storage Systems EMC
This EMC Engineering TechBook provides a general description of EMC products that can be used for DB2 administration on z/OS. Using EMC products to manage DB2 environments can reduce database and storage management administration, reduce CPU resource consumption, and reduce the time required to clone, back up, or recover DB2 systems
A virtual local area network (VLAN) is defined in a switch that sets the boundary of a
broadcast domain for hosts to communicate with each other. A VLAN has the same attributes
as a physical local area network (LAN) and it can be extended between different switches
within or across different sites.
Today, VLANs are created in the switch to mimic the Ethernet segmentation services that are
traditionally provided by the routers in LAN configurations. Figure 1-1 gives a conceptual view
of a VLAN.
MetaFabric™ Architecture Virtualized Data Center: Design and Implementation G...Juniper Networks
The benefits of virtualization are driving data center operators to rethink their legacy data center networks and look for new ways to reduce costs and improve efficiency in the data center. Moving from a legacy network to a state-of-the-art solution allows you to deploy new applications in seconds rather than days, weeks, or months. If you want to harness the power of virtualization in your data center network, this guide will help you to achieve your goal.
Cenet-- capability enabled networking: towards least-privileged networkingJithu Joseph
In today's IP networks, any host can send packets to any other host irrespective of whether the recipient is interested in communicating with the sender or not. The downside of this openness is that every host is vulnerable to an attack by any other host. We ob- serve that this unrestricted network access (network ambient authority) from compromised systems is also a main reason for data exfiltration attacks within corporate networks. We address this issue using the network version of capability based access control. We bring the idea of capabilities and capability-based access control to the domain of networking. CeNet provides policy driven, fine-grained network level access control enforced in the core of the network (and not at the end-hosts) thereby removing network ambient authority. Thus CeNet is able to limit the scope of spread of an attack from a compromised host to other hosts in the network. We built a capability-enabled SDN network where communication privileges of an endpoint are limited according to its function in the network. Network capabilities can be passed between hosts, thereby allowing a delegation-oriented security policy to be realized. We believe that this base functionality can pave the way for the realization of sophisticated security policies within an enterprise network. Further we built a policy manager that is able to realize Role-Based Access Control (RBAC) policy based network access control using capability operations. We also look at some of the results of formal analysis of capability propagation models in the context of networks.
Intel and Siveo wrote this content which explain how their Cloud Orchestrator is working. You will learn how to configure it, benefit from automatical workload placement feature and manage multiple hypervisors transparently.
INDUSTRY-LEADING TECHNOLOGY FOR LONG TERM RETENTION OF BACKUPS IN THE CLOUDEMC
CloudBoost is a cloud-enabling solution from EMC
Facilitates secure, automatic, efficient data transfer to private and public clouds for Long-Term Retention (LTR) of backups. Seamlessly extends existing data protection solutions to elastic, resilient, scale-out cloud storage
Transforming Desktop Virtualization with Citrix XenDesktop and EMC XtremIOEMC
With EMC XtremIO all-flash array, improve
1) your competitive agility with real-time analytics & development
2) your infrastructure agility with elastic provisioning for performance & capacity
3) your TCO with 50% lower capex and opex and double the storage lifecycle.
• Citrix & EMC XtremIO: Better Together
• XtremIO Design Fundamentals for VDI
• Citrix XenDesktop & XtremIO
-- Image Management & Storage
-- Demonstrations
-- XtremIO XenDesktop Integration
EMC FORUM RESEARCH GLOBAL RESULTS - 10,451 RESPONSES ACROSS 33 COUNTRIES EMC
Explore findings from the EMC Forum IT Study and learn how cloud computing, social, mobile, and big data megatrends are shaping IT as a business driver globally.
Reference architecture with MIRANTIS OPENSTACK PLATFORM.The changes that are going on in IT with disruptions from technology, business and culture and so IT to solve the issues has to change from moving from traditional models to broker provider model.
Force Cyber Criminals to Shop Elsewhere
Learn the value of having an Identity Management and Governance solution and how retailers today are benefiting by strengthening their defenses and bolstering their Identity Management capabilities.
Container-based technology has experienced a recent revival and is becoming adopted at an explosive rate. For those that are new to the conversation, containers offer a way to virtualize an operating system. This virtualization isolates processes, providing limited visibility and resource utilization to each, such that the processes appear to be running on separate machines. In short, allowing more applications to run on a single machine. Here is a brief timeline of key moments in container history.
This white paper provides an overview of EMC's data protection solutions for the data lake - an active repository to manage varied and complex Big Data workloads
This infographic highlights key stats and messages from the analyst report from J.Gold Associates that addresses the growing economic impact of mobile cybercrime and fraud.
This white paper describes how an intelligence-driven governance, risk management, and compliance (GRC) model can create an efficient, collaborative enterprise GRC strategy across IT, Finance, Operations, and Legal areas.
The Trust Paradox: Access Management and Trust in an Insecure AgeEMC
This white paper discusses the results of a CIO UK survey on a“Trust Paradox,” defined as employees and business partners being both the weakest link in an organization’s security as well as trusted agents in achieving the company’s goals.
LF Energy Webinar: Electrical Grid Modelling and Simulation Through PowSyBl -...DanBrown980551
Do you want to learn how to model and simulate an electrical network from scratch in under an hour?
Then welcome to this PowSyBl workshop, hosted by Rte, the French Transmission System Operator (TSO)!
During the webinar, you will discover the PowSyBl ecosystem as well as handle and study an electrical network through an interactive Python notebook.
PowSyBl is an open source project hosted by LF Energy, which offers a comprehensive set of features for electrical grid modelling and simulation. Among other advanced features, PowSyBl provides:
- A fully editable and extendable library for grid component modelling;
- Visualization tools to display your network;
- Grid simulation tools, such as power flows, security analyses (with or without remedial actions) and sensitivity analyses;
The framework is mostly written in Java, with a Python binding so that Python developers can access PowSyBl functionalities as well.
What you will learn during the webinar:
- For beginners: discover PowSyBl's functionalities through a quick general presentation and the notebook, without needing any expert coding skills;
- For advanced developers: master the skills to efficiently apply PowSyBl functionalities to your real-world scenarios.
Accelerate your Kubernetes clusters with Varnish CachingThijs Feryn
A presentation about the usage and availability of Varnish on Kubernetes. This talk explores the capabilities of Varnish caching and shows how to use the Varnish Helm chart to deploy it to Kubernetes.
This presentation was delivered at K8SUG Singapore. See https://feryn.eu/presentations/accelerate-your-kubernetes-clusters-with-varnish-caching-k8sug-singapore-28-2024 for more details.
Neuro-symbolic is not enough, we need neuro-*semantic*Frank van Harmelen
Neuro-symbolic (NeSy) AI is on the rise. However, simply machine learning on just any symbolic structure is not sufficient to really harvest the gains of NeSy. These will only be gained when the symbolic structures have an actual semantics. I give an operational definition of semantics as “predictable inference”.
All of this illustrated with link prediction over knowledge graphs, but the argument is general.
Securing your Kubernetes cluster_ a step-by-step guide to success !KatiaHIMEUR1
Today, after several years of existence, an extremely active community and an ultra-dynamic ecosystem, Kubernetes has established itself as the de facto standard in container orchestration. Thanks to a wide range of managed services, it has never been so easy to set up a ready-to-use Kubernetes cluster.
However, this ease of use means that the subject of security in Kubernetes is often left for later, or even neglected. This exposes companies to significant risks.
In this talk, I'll show you step-by-step how to secure your Kubernetes cluster for greater peace of mind and reliability.
State of ICS and IoT Cyber Threat Landscape Report 2024 previewPrayukth K V
The IoT and OT threat landscape report has been prepared by the Threat Research Team at Sectrio using data from Sectrio, cyber threat intelligence farming facilities spread across over 85 cities around the world. In addition, Sectrio also runs AI-based advanced threat and payload engagement facilities that serve as sinks to attract and engage sophisticated threat actors, and newer malware including new variants and latent threats that are at an earlier stage of development.
The latest edition of the OT/ICS and IoT security Threat Landscape Report 2024 also covers:
State of global ICS asset and network exposure
Sectoral targets and attacks as well as the cost of ransom
Global APT activity, AI usage, actor and tactic profiles, and implications
Rise in volumes of AI-powered cyberattacks
Major cyber events in 2024
Malware and malicious payload trends
Cyberattack types and targets
Vulnerability exploit attempts on CVEs
Attacks on counties – USA
Expansion of bot farms – how, where, and why
In-depth analysis of the cyber threat landscape across North America, South America, Europe, APAC, and the Middle East
Why are attacks on smart factories rising?
Cyber risk predictions
Axis of attacks – Europe
Systemic attacks in the Middle East
Download the full report from here:
https://sectrio.com/resources/ot-threat-landscape-reports/sectrio-releases-ot-ics-and-iot-security-threat-landscape-report-2024/
GraphRAG is All You need? LLM & Knowledge GraphGuy Korland
Guy Korland, CEO and Co-founder of FalkorDB, will review two articles on the integration of language models with knowledge graphs.
1. Unifying Large Language Models and Knowledge Graphs: A Roadmap.
https://arxiv.org/abs/2306.08302
2. Microsoft Research's GraphRAG paper and a review paper on various uses of knowledge graphs:
https://www.microsoft.com/en-us/research/blog/graphrag-unlocking-llm-discovery-on-narrative-private-data/
UiPath Test Automation using UiPath Test Suite series, part 4DianaGray10
Welcome to UiPath Test Automation using UiPath Test Suite series part 4. In this session, we will cover Test Manager overview along with SAP heatmap.
The UiPath Test Manager overview with SAP heatmap webinar offers a concise yet comprehensive exploration of the role of a Test Manager within SAP environments, coupled with the utilization of heatmaps for effective testing strategies.
Participants will gain insights into the responsibilities, challenges, and best practices associated with test management in SAP projects. Additionally, the webinar delves into the significance of heatmaps as a visual aid for identifying testing priorities, areas of risk, and resource allocation within SAP landscapes. Through this session, attendees can expect to enhance their understanding of test management principles while learning practical approaches to optimize testing processes in SAP environments using heatmap visualization techniques
What will you get from this session?
1. Insights into SAP testing best practices
2. Heatmap utilization for testing
3. Optimization of testing processes
4. Demo
Topics covered:
Execution from the test manager
Orchestrator execution result
Defect reporting
SAP heatmap example with demo
Speaker:
Deepak Rai, Automation Practice Lead, Boundaryless Group and UiPath MVP
DevOps and Testing slides at DASA ConnectKari Kakkonen
My and Rik Marselis slides at 30.5.2024 DASA Connect conference. We discuss about what is testing, then what is agile testing and finally what is Testing in DevOps. Finally we had lovely workshop with the participants trying to find out different ways to think about quality and testing in different parts of the DevOps infinity loop.
Transcript: Selling digital books in 2024: Insights from industry leaders - T...BookNet Canada
The publishing industry has been selling digital audiobooks and ebooks for over a decade and has found its groove. What’s changed? What has stayed the same? Where do we go from here? Join a group of leading sales peers from across the industry for a conversation about the lessons learned since the popularization of digital books, best practices, digital book supply chain management, and more.
Link to video recording: https://bnctechforum.ca/sessions/selling-digital-books-in-2024-insights-from-industry-leaders/
Presented by BookNet Canada on May 28, 2024, with support from the Department of Canadian Heritage.
Builder.ai Founder Sachin Dev Duggal's Strategic Approach to Create an Innova...Ramesh Iyer
In today's fast-changing business world, Companies that adapt and embrace new ideas often need help to keep up with the competition. However, fostering a culture of innovation takes much work. It takes vision, leadership and willingness to take risks in the right proportion. Sachin Dev Duggal, co-founder of Builder.ai, has perfected the art of this balance, creating a company culture where creativity and growth are nurtured at each stage.
Elevating Tactical DDD Patterns Through Object CalisthenicsDorra BARTAGUIZ
After immersing yourself in the blue book and its red counterpart, attending DDD-focused conferences, and applying tactical patterns, you're left with a crucial question: How do I ensure my design is effective? Tactical patterns within Domain-Driven Design (DDD) serve as guiding principles for creating clear and manageable domain models. However, achieving success with these patterns requires additional guidance. Interestingly, we've observed that a set of constraints initially designed for training purposes remarkably aligns with effective pattern implementation, offering a more ‘mechanical’ approach. Let's explore together how Object Calisthenics can elevate the design of your tactical DDD patterns, offering concrete help for those venturing into DDD for the first time!
Mission to Decommission: Importance of Decommissioning Products to Increase E...
TechBook: EMC VPLEX Metro Witness Technology and High Availability
1. EMC VPLEX Metro Witness
Technology and High Availability
Version 2.1
• EMC VPLEX Witness
• VPLEX Metro High Availability
• Metro HA Deployment Scenarios
Jennifer Aspesi
Oliver Shorey
3. Contents
Preface
Chapter 1 VPLEX Family and Use Case Overview
Introduction ....................................................................................... 18
VPLEX value overview .................................................................... 19
VPLEX product offerings ................................................................ 23
VPLEX Local, VPLEX Metro, and VPLEX Geo ......................23
Architecture highlights ..............................................................25
Metro high availability design considerations ............................. 28
Planned application mobility compared with disaster
restart ...........................................................................................29
Chapter 2 Hardware and Software
Introduction ....................................................................................... 32
VPLEX I/O ..................................................................................32
High-level VPLEX I/O flow......................................................32
Distributed coherent cache........................................................33
VPLEX family clustering architecture ....................................33
VPLEX single, dual, and quad engines ...................................35
VPLEX sizing tool.......................................................................35
Upgrade paths.............................................................................36
Hardware upgrades ...................................................................36
Software upgrades......................................................................36
VPLEX management interfaces ...................................................... 37
Web-based GUI ...........................................................................37
VPLEX CLI...................................................................................37
SNMP support for performance statistics...............................38
LDAP /AD support ...................................................................38
EMC VPLEX Metro Witness Technology and High Availability 3
4. Contents
VPLEX Element Manager API.................................................. 38
Simplified storage management..................................................... 39
Management server user accounts................................................. 40
Management server software.......................................................... 41
Management console ................................................................. 41
Command line interface ............................................................ 43
System reporting......................................................................... 44
Director software .............................................................................. 45
Configuration overview................................................................... 46
Single engine configurations..................................................... 46
Dual configurations.................................................................... 47
Quad configurations .................................................................. 48
I/O implementation ......................................................................... 50
Cache coherence ......................................................................... 50
Meta-directory ............................................................................ 50
How a read is handled............................................................... 50
How a write is handled ............................................................. 52
Chapter 3 System and Component Integrity
Overview............................................................................................ 54
Cluster ................................................................................................ 55
Path redundancy through different ports ..................................... 56
Path redundancy through different directors............................... 57
Path redundancy through different engines................................. 58
Path redundancy through site distribution .................................. 59
Serviceability ..................................................................................... 60
Chapter 4 Foundations of VPLEX High Availability
Foundations of VPLEX High Availability .................................... 62
Failure handling without VPLEX Witness (static preference).... 70
Chapter 5 Introduction to VPLEX Witness
VPLEX Witness overview and architecture .................................. 82
VPLEX Witness target solution, rules, and best practices .......... 85
VPLEX Witness failure semantics................................................... 87
CLI example outputs........................................................................ 93
VPLEX Witness – The importance of the third failure
domain ......................................................................................... 97
4 EMC VPLEX Metro Witness Technology and High Availability
5. Contents
Chapter 6 VPLEX Metro HA
VPLEX Metro HA overview .......................................................... 100
VPLEX Metro HA Campus (with cross-connect) ...................... 101
VPLEX Metro HA (without cross-cluster connection)............... 111
Chapter 7 Conclusion
Conclusion........................................................................................ 120
Better protection from storage-related failures ....................121
Protection from a larger array of possible failures...............121
Greater overall resource utilization........................................122
Glossary
EMC VPLEX Metro Witness Technology and High Availability 5
6. Contents
6 EMC VPLEX Metro Witness Technology and High Availability
7. Figures
Title Page
1 Application and data mobility example ..................................................... 20
2 HA infrastructure example ........................................................................... 21
3 Distributed data collaboration example ..................................................... 22
4 VPLEX offerings ............................................................................................. 24
5 Architecture highlights.................................................................................. 26
6 VPLEX cluster example ................................................................................. 34
7 VPLEX Management Console ...................................................................... 42
8 Management Console welcome screen ....................................................... 43
9 VPLEX single engine configuration............................................................. 47
10 VPLEX dual engine configuration ............................................................... 48
11 VPLEX quad engine configuration .............................................................. 49
12 Port redundancy............................................................................................. 56
13 Director redundancy...................................................................................... 57
14 Engine redundancy ........................................................................................ 58
15 Site redundancy.............................................................................................. 59
16 High level functional sites in communication ........................................... 62
17 High level Site A failure ................................................................................ 63
18 High level Inter-site link failure ................................................................... 63
19 VPLEX active and functional between two sites ....................................... 64
20 VPLEX concept diagram with failure at Site A.......................................... 65
21 Correct resolution after volume failure at Site A....................................... 66
22 VPLEX active and functional between two sites ....................................... 67
23 Inter-site link failure and cluster partition ................................................. 68
24 Correct handling of cluster partition........................................................... 69
25 VPLEX static detach rule............................................................................... 71
26 Typical detach rule setup .............................................................................. 72
27 Non-preferred site failure ............................................................................. 73
28 Volume remains active at Cluster 1............................................................. 74
29 Typical detach rule setup before link failure ............................................. 75
30 Inter-site link failure and cluster partition ................................................. 76
EMC VPLEX Metro Witness Technology and High Availability 7
8. Figures
31 Suspension after inter-site link failure and cluster partition ................... 77
32 Cluster 2 is preferred ..................................................................................... 78
33 Preferred site failure causes full Data Unavailability ............................... 79
34 High Level VPLEX Witness architecture.................................................... 83
35 High Level VPLEX Witness deployment .................................................. 84
36 Supported VPLEX versions for VPLEX Witness ....................................... 86
37 VPLEX Witness volume types and rule support....................................... 86
38 Typical VPLEX Witness configuration ....................................................... 87
39 VPLEX Witness and an inter-cluster link failure....................................... 88
40 VPLEX Witness and static preference after cluster partition................... 89
41 VPLEX Witness typical configuration for cluster 2 detaches .................. 90
42 VPLEX Witness diagram showing cluster 2 failure .................................. 91
43 VPLEX Witness with static preference override........................................ 92
44 Possible dual failure cluster isolation scenarios ........................................ 95
45 Highly unlikely dual failure scenarios that require manual
intervention ..................................................................................................... 96
46 Two further dual failure scenarios that would require manual
intervention ..................................................................................................... 97
47 High-level diagram of a Metro HA campus solution for VMware ...... 101
48 Metro HA campus diagram with failure domains.................................. 104
49 Metro HA campus diagram with disaster in zone A1............................ 105
50 Metro HA campus diagram with failure in zone A2.............................. 106
51 Metro HA campus diagram with failure in zone A3 or B3.................... 107
52 Metro HA campus diagram with failure in zone C1 .............................. 108
53 Metro HA campus diagram with intersite link failure........................... 109
54 Metro HA Standard High-level diagram ................................................. 111
55 Metro HA high-level diagram with fault domains ................................. 113
56 Metro HA high-level diagram with failure in domain A2..................... 114
57 Metro HA high-level diagram with intersite failure.............................. 116
8 EMC VPLEX Metro Witness Technology and High Availability
9. Tables
Title Page
1 Overview of VPLEX features and benefits .................................................. 26
2 Configurations at a glance ............................................................................. 35
3 Management server user accounts ............................................................... 40
EMC VPLEX Metro Witness Technology and High Availability 9
10. Tables
10 EMC VPLEX Metro Witness Technology and High Availability
11. Preface
This EMC Engineering TechBook describes and provides an insightful
discussion on how implementation of VPLEX will lead to a higher level of
availability.
As part of an effort to improve and enhance the performance and capabilities
of its product lines, EMC periodically releases revisions of its hardware and
software. Therefore, some functions described in this document may not be
supported by all versions of the software or hardware currently in use. For
the most up-to-date information on product features, refer to your product
release notes. If a product does not function properly or does not function as
described in this document, please contact your EMC representative.
Audience This document is part of the EMC VPLEX family documentation set,
and is intended for use by storage and system administrators.
Readers of this document are expected to be familiar with the
following topics:
◆ Storage area networks
◆ Storage virtualization technologies
◆ EMC Symmetrix, VNX series, and CLARiiON products
Related Refer the EMC Powerlink website at http://powerlink.emc.com
documentation where the majority of the following documentation can be found
under Support > Technical Documentation and Advisories >
Hardware Platforms > VPLEX Family.
◆ EMC VPLEX Architecture Guide
◆ EMC VPLEX Installation and Setup Guide
◆ EMC VPLEX Site Preparation Guide
EMC VPLEX Metro Witness Technology and High Availability 11
12. Preface
◆ Implementation and Planning Best Practices for EMC VPLEX
Technical Notes
◆ Using VMware Virtualization Platforms with EMC VPLEX - Best
Practices Planning
◆ VMware KB: Using VPLEX Metro with VMware HA
◆ Implementing EMC VPLEX Metro with Microsoft Hyper-V, Exchange
Server 2010 with Enhanced Failover Clustering Support
◆ White Paper: Using VMware vSphere with EMC VPLEX — Best
Practices Planning
◆ Oracle Extended RAC with EMC VPLEX Metro—Best Practices
Planning
◆ White Paper: EMC VPLEX with IBM AIX Virtualization and
Clustering
◆ White Paper: Conditions for Stretched Hosts Cluster Support on EMC
VPLEX Metro
◆ White Paper: Implementing EMC VPLEX and Microsoft Hyper-V and
SQL Server with Enhanced Failover Clustering Support — Applied
Technology
Organization of this This document is divided into the following chapters:
TechBook
◆ Chapter 1, “VPLEX Family and Use Case Overview,”
summarizes the VPLEX family. It also covers some of the key
features of the VPLEX family system, architecture and use cases.
◆ Chapter 2, “Hardware and Software,” summarizes hardware,
software, and network components of the VPLEX system. It also
highlights the software interfaces that can be used by an
administrator to manage all aspects of a VPLEX system.
◆ Chapter 3, “System and Component Integrity,” summarizes how
VPLEX clusters are able to handle hardware failures in any
subsystem within the storage cluster.
◆ Chapter 4, “Foundations of VPLEX High Availability,”
summarizes the concepts of the industry-wide dilemma of
building absolute HA environments and how VPLEX Metro
functionality manually accepts the historical challenge.
◆ Chapter 5, “Introduction to VPLEX Witness,” explains VPLEX
architecture and operation.
12 EMC VPLEX Metro Witness Technology and High Availability
13. Preface
◆ Chapter 6, “VPLEX Metro HA,” explains how VPLEX
functionality can provide the absolute HA capability, by
introducing a “Witness” to the inter-cluster environment.
◆ Chapter 7, “Conclusion,” provides a summary of benefits using
VPLEX technology as related to VPLEX Witness and High
Availability.
◆ Appendix A, “vSphere 5.0 Update 1 Additional Settings,”
provides additional settings needed when using vSphere 5.0
update 1.
Authors This TechBook was authored by the following individuals from the
Enterprise Storage Division, VPLEX Business Unit based at EMC
headquarters, Hopkinton, Massachusetts.
Jennifer Aspesi has over 10 years of work experience with EMC in
Storage Area Networks (SAN), Wide Area Networks (WAN), and
Network and Storage Security technologies. Jen currently manages
the Corporate Systems Engineer team for the VPLEX Business Unit.
She earned her M.S. in Marketing and Technological Innovation from
Worcester Polytech Institute, Massachusetts.
Oliver Shorey has over 11 years experience working within the
Business Continuity arena, seven of which have been with EMC
engineering, designing and documenting high-end replication and
geographically-dispersed clustering technologies. He is currently a
Principal Corporate Systems Engineer in the VPLEX Business Unit.
Additional Additional contributors to this book include:
contributors
Colin Durocher has 8 years of experience in developing software for
the EMC VPLEX product as its predecessor and current state, testing
it, and helping customers implement it. He is currently working on
the product management team for the VPLEX business unit. He has a
B.S. in Computer Engineering from the University of Alberta and is
currently pursuing an MBA from the John Molson School of Business.
Gene Ortenberg has more than 15 years of experience in building
fault-tolerant distributed systems and applications. For the past 8
years he has been designing and developing highly-available storage
virtualization solutions at EMC. He currently holds a position of a
Software Architect for the VPLEX Business Unit under the EMC
Enterprise Storage Division.
EMC VPLEX Metro Witness Technology and High Availability 13
14. Preface
Fernanda Torres has over 10 years of Marketing experience in the
Consumer Products industry, most recently in consumer electronics.
Fernanda is the Product Marketing Manager for VPLEX under the
EMC Enterprise Storage Division. She has undergraduate degree
from the University of Notre Dame and a bilingual degree
(English/Spanish) from IESE in Barcelona, Spain.
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14 EMC VPLEX Metro Witness Technology and High Availability
15. Preface
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EMC VPLEX Metro Witness Technology and High Availability 15
16. Preface
16 EMC VPLEX Metro Witness Technology and High Availability
17. 1
VPLEX Family and Use
Case Overview
This chapter provides a brief summary of the main use cases for the
EMC VPLEX family and design considerations for high availability. It
also covers some of the key features of the VPLEX family system.
Topics include:
◆ Introduction ........................................................................................ 18
◆ VPLEX value overview ..................................................................... 19
◆ VPLEX product offerings ................................................................. 23
◆ Metro high availability design considerations .............................. 28
VPLEX Family and Use Case Overview 17
18. VPLEX Family and Use Case Overview
Introduction
The purpose of this TechBook is to introduce EMC® VPLEX™ high
availability and the VPLEX Witness as it is conceptually
architectured, typically by customer storage administrators and EMC
Solutions Architects. The introduction of VPLEX Witness provides
customers with absolute physical and logical fabric and cache
coherent redundancy if it is properly designed in the VPLEX Metro
environment.
This TechBook is designed to provide an overview of the features and
functionality associated with the VPLEX Metro configuration and the
importance of active/active data resiliency for today’s advanced host
applications.
18 EMC VPLEX Metro Witness Technology and High Availability
19. VPLEX Family and Use Case Overview
VPLEX value overview
At the highest level, VPLEX has unique capabilities that storage
administrators value and are seeking to enhance their existing data
centers. It delivers distributed, dynamic and smart functionality into
existing or new data centers to provide storage virtualization across
geographical boundaries.
◆ VPLEX is distributed, because it is a single interface for
multi-vendor storage and it delivers dynamic data mobility,
enabling the ability to move applications and data in real-time,
with no outage required.
◆ VPLEX is dynamic, because it provides data availability and
flexibility as well as maintaining business through failures
traditionally requiring outages or manual restore procedures.
◆ VPLEX is smart, because its unique AccessAnywhere technology
can present and keep the same data consistent within and
between sites and enable distributed data collaboration.
Because of these capabilities, VPLEX delivers unique and
differentiated value to address three distinct requirements within our
target customers’ IT environments:
◆ The ability to dynamically move applications and data across
different compute and storage installations, be they within the
same data center, across a campus, within a geographical region –
and now, with VPLEX Geo, across even greater distances.
◆ The ability to create high-availability storage and a compute
infrastructure across these same varied geographies with
unmatched resiliency.
◆ The ability to provide efficient real-time data collaboration over
distance for such “big data” applications as video, geographic
/oceanographic research, and more.
EMC VPLEX technology is a scalable, distributed-storage federation
solution that provides non-disruptive, heterogeneous
data-movement and volume-management functionality.
Insert VPLEX technology between hosts and storage in a storage area
network (SAN) and data can be extended over distance within,
between, and across data centers.
VPLEX value overview 19
20. VPLEX Family and Use Case Overview
The VPLEX architecture provides a highly available solution suitable
for many deployment strategies including:
◆ Application and Data Mobility — The movement of virtual
machines (VM) without downtime. An example is shown in
Figure 1.
Figure 1 Application and data mobility example
Storage administrators have the ability to automatically balance
loads through VPLEX, using storage and compute resources from
either cluster’s location. When combined with server
virtualization, VPLEX allows users to transparently move and
relocate Virtual Machines and their corresponding applications
and data over distance. This provides a unique capability allowing
users to relocate, share and balance infrastructure resources
between sites, which can be within a campus or between data
centers, up to 5ms apart with VPLEX Metro, or further apart
(50ms RTT) across asynchronous distances with VPLEX Geo.
Note: Please submit an RPQ if VPLEX Metro is required up to 10ms or check
the support matrix for the latest supported latencies.
20 EMC VPLEX Metro Witness Technology and High Availability
21. VPLEX Family and Use Case Overview
• HA Infrastructure — Reduces recovery time objective (RTO).
An example is shown in Figure 2.
Figure 2 HA infrastructure example
High availability is a term that several products will claim they
can deliver. Ultimately, a high availability solution is supposed to
protect against a failure and keep an application online. Storage
administrators plan around HA to provide near continuous
uptime for their critical applications, and automate the restart of
an application once a failure has occurred, with as little human
intervention as possible.
With conventional solutions, customers typically have to choose a
Recovery Point Objective and a Recovery Time Objective. But
even while some solutions offer small RTOs and RPOs, there can
still be downtime and, for most customers, any downtime can be
costly.
VPLEX value overview 21
22. VPLEX Family and Use Case Overview
• Distributed Data Collaboration — Increases utilization of
passive data recovery (DR) assets and provides simultaneous
access to data. An example is shown in Figure 3.
Figure 3 Distributed data collaboration example
• This is when a workforce has multiple users at different sites
that need to work on the same data, and maintain consistency
in the dataset when changes are made. Use cases include
co-development of software where the development happens
across different teams from separate locations, and
collaborative workflows such as engineering, graphic arts,
videos, educational programs, designs, research reports, and
so forth.
• When customers have tried to build collaboration across
distance with the traditional solutions, they normally have to
save the entire file at one location and then send it to another
site using FTP. This is slow, can incur heavy bandwidth costs
for large files, or even small files that move regularly, and
negatively impacts productivity because the other sites can sit
idle while they wait to receive the latest data from another site.
If teams decide to do their own work independent of each
other, then the dataset quickly becomes inconsistent, as
multiple people are working on it at the same time and are
unaware of each other’s most recent changes. Bringing all of
the changes together in the end is time-consuming, costly, and
grows more complicated as the data-set gets larger.
22 EMC VPLEX Metro Witness Technology and High Availability
23. VPLEX Family and Use Case Overview
VPLEX product offerings
VPLEX first meets high-availability and data mobility requirements
and then scales up to the I/O throughput required for the front-end
applications and back-end storage.
High-availability and data mobility features are characteristics of
VPLEX Local, VPLEX Metro, and VPLEX Geo.
A VPLEX cluster consists of one, two, or four engines (each
containing two directors), and a management server. A dual-engine
or quad-engine cluster also contains a pair of Fibre Channel switches
for communication between directors.
Each engine is protected by a standby power supply (SPS), and each
Fibre Channel switch gets its power through an uninterruptible
power supply (UPS). (In a dual-engine or quad-engine cluster, the
management server also gets power from a UPS.)
The management server has a public Ethernet port, which provides
cluster management services when connected to the customer
network.
This section provides information on the following:
◆ “VPLEX Local, VPLEX Metro, and VPLEX Geo” on page 23
◆ “Architecture highlights” on page 25
VPLEX Local, VPLEX Metro, and VPLEX Geo
EMC offers VPLEX in three configurations to address customer needs
for high-availability and data mobility:
◆ VPLEX Local
◆ VPLEX Metro
◆ VPLEX Geo
VPLEX product offerings 23
24. VPLEX Family and Use Case Overview
Figure 4 provides an example of each.
Figure 4 VPLEX offerings
VPLEX Local
VPLEX Local provides seamless, non-disruptive data mobility and
ability to manage multiple heterogeneous arrays from a single
interface within a data center.
VPLEX Local allows increased availability, simplified management,
and improved utilization across multiple arrays.
VPLEX Metro with AccessAnywhere
VPLEX Metro with AccessAnywhere enables active-active, block
level access to data between two sites within synchronous distances.
The distance is limited as to what Synchronous behavior can
withstand as well as consideration to host application stability and
MAN traffic. It is recommended that depending on the application
that consideration for Metro be less than or equal to 5ms1 RTT.
The combination of virtual storage with VPLEX Metro and virtual
servers enables the transparent movement of virtual machines and
storage across a distance.This technology provides improved
utilization across heterogeneous arrays and multiple sites.
1. Refer to VPLEX and vendor-specific White Papers for confirmation of
latency limitations.
24 EMC VPLEX Metro Witness Technology and High Availability
25. VPLEX Family and Use Case Overview
VPLEX Geo with AccessAnywhere
VPLEX Geo with AccessAnywhere enables active-active, block level
access to data between two sites within asynchronous distances.
VPLEX Geo enables better cost-effective use of resources and power.
Geo provides the same distributed device flexibility as Metro but
extends the distance up to and within 50ms RTT. As with any
Asynchronous transport media, bandwidth is also important to
consider for optimal behavior as well as application sharing on the
link.
Note: For the purpose of this TechBook, the focus on technologies is
based on Metro configuration only. VPLEX Witness is supported with
VPLEX Geo; however, it is beyond the scope of this TechBook.
Architecture highlights
VPLEX support is open and heterogeneous, supporting both EMC
storage and common arrays from other storage vendors, such as
HDS, HP, and IBM. VPLEX conforms to established worldwide
naming (WWN) guidelines that can be used for zoning.
VPLEX supports operating systems including both physical and
virtual server environments with VMware ESX and Microsoft
Hyper-V. VPLEX supports network fabrics from Brocade and Cisco,
including legacy McData SANs.
Note: For the latest information please refer to the ESSM (EMC
Simple Support Matrix) for supported host types as well as the
connectivity ESM for fabric and extended fabric support.
VPLEX product offerings 25
26. VPLEX Family and Use Case Overview
An example of the architecture is shown in Figure 5.
Figure 5 Architecture highlights
Table 1 lists an overview of VPLEX features along with the benefits.
Table 1 Overview of VPLEX features and benefits (page 1 of 2)
Features Benefits
Mobility Move data and applications without impact on
users.
Resiliency Mirror across arrays without host impact, and
increase high availability for critical applications.
Distributed cache coherency Automate sharing, balancing, and failover of I/O
across the cluster and between clusters.
26 EMC VPLEX Metro Witness Technology and High Availability
27. VPLEX Family and Use Case Overview
Table 1 Overview of VPLEX features and benefits (page 2 of 2)
Features Benefits
Advanced data caching Improve I/O performance and reduce storage array
contention.
Virtual Storage federation Achieve transparent mobility and access in a data
center and between data centers.
Scale-out cluster architecture Start small and grow larger with predictable service
levels.
For all VPLEX products, the appliance-based VPLEX technology:
◆ Presents storage area network (SAN) volumes from back-end
arrays to VPLEX engines
◆ Packages the SAN volumes into sets of VPLEX virtual volumes
with user-defined configuration and protection levels
◆ Presents virtual volumes to production hosts in the SAN via the
VPLEX front-end
◆ For VPLEX Metro and VPLEX Geo products, presents a global,
block-level directory for distributed cache and I/O between
VPLEX clusters.
Location and distance determine high-availability and data mobility
requirements. For example, if all storage arrays are in a single data
center, a VPLEX Local product federates back-end storage arrays
within the data center.
When back-end storage arrays span two data centers, the
AccessAnywhere feature in a VPLEX Metro or a VPLEX Geo product
federates storage in an active-active configuration between VPLEX
clusters. Choosing between VPLEX Metro or VPLEX Geo depends on
distance and data synchronicity requirements.
Application and back-end storage I/O throughput determine the
number of engines in each VPLEX cluster. High-availability features
within the VPLEX cluster allow for non-disruptive software upgrades
and expansion as I/O throughput increases.
VPLEX product offerings 27
28. VPLEX Family and Use Case Overview
Metro high availability design considerations
VPLEX Metro 5.0 (and above) introduces high availability concepts
beyond what is traditionally known as physical high availability.
Introduction of the “VPLEX Witness” to a high availability
environment, allows the VPLEX solution to increase the overall
availability of the environment by arbitrating a pure communication
failure between two primary sites and a true site failure in a multi-site
architecture. EMC VPLEX is the first product to bring to market the
features and functionality provided by VPLEX Witness prevents
failures and asserts the activity between clusters in a multi-site
architecture.
Through this TechBook, administrators and customers gain an
understanding of the high availability solution that VPLEX provides
them:
◆ Enabling of load balancing between their data centers
◆ Active/active use of both of their data centers
◆ Increased availability for their applications (no single points of
storage failure, auto-restart)
◆ Fully automatic failure handling
◆ Better resource utilization
◆ Lower CapEx and lower OpEx as a result
Broadly speaking, when one considers legacy environments one
typically sees “highly” available designs implemented within a data
center, and disaster recovery type functionality deployed between
data centers.
One of the main reasons for this is that within data centers
components generally operate in an active/active (or active/passive
with automatic failover) whereas between data centers legacy
replication technologies use active passive techniques which require
manual failover to use the passive component.
When using VPLEX Metro active/active replication technology in
conjunction with new features, such as VPLEX Witness server (as
described in “Introduction to VPLEX Witness” on page 81), the lines
between local high availability and long distance disaster recovery
are somewhat blurred since HA can be stretched beyond the data
28 EMC VPLEX Metro Witness Technology and High Availability
29. VPLEX Family and Use Case Overview
center walls. Since replication is a by-product of federated and
distributed storage disaster avoidance, it is also achievable within
these geographically dispersed HA environments.
Planned application mobility compared with disaster restart
This section compares planned application mobility and disaster
restart.
Planned application An online planned application mobility event is defined as when an
mobility application or virtual machine can be moved fully online without
disruption from one location to another in either the same or remote
data center. This type of movement can only be performed when all
components that participate in this movement are available (e.g., the
running state of the application or VM exists in volatile memory
which would not be the case if an active site has failed) and if all
participating hosts have read/write access at both location to the
same block storage. Additional a mechanism is required to transition
volatile memory data from one system/host to another. When
performing planned online mobility jobs over distance a prerequisite
y is the use of an active/active underlying storage replication
solution (VPLEX Metro only at this publication).
An example of this online application mobility would be VMware
vMotion where a virtual machine would need to be fully operational
before it can be moved. It may sound obvious but if the VM was
offline then movement could not be performed online (This is
important to understand and is the key difference over application
restart).
When vMotion is executed all live components that are required to
make the VM function are copied elsewhere in the background before
cutting the VM over.
Since these types of mobility tasks are totally seamless to the user
some of the use cases associated are for disaster avoidance where an
application or VM can be moved ahead of a disaster (such as,
Hurricane, Tsunami, etc.) as the running state is available to be
copied, or in other cases it can be used to enable the ability to load
balance across multiple systems or even data centers.
Due to the need for the running state to be available for these types of
relocations these movements are always deemed planned activities.
Metro high availability design considerations 29
30. VPLEX Family and Use Case Overview
Disaster restart Disaster restart is where an application or service is re-started in
another location after a failure (be it on a different server or data
center) and will typically interrupt the service/application during the
failover.
A good example of this technology would be a VMware HA Cluster
configured over two geographically dispersed sites using VPLEX
Metro where a cluster will be formed over a number of ESX servers
and either single or multiple virtual machines can run on any of the
ESX servers within the cluster.
If for some reason an active ESX server were to fail (perhaps due to
site failure) then the VM can be re-started on a remaining ESX server
within the cluster at the remote site as the datastore where it was
running spans the two locations since it is configured on a VPLEX
Metro distributed volume. This would be deemed an unplanned
failover which will incur a small outage of the application since the
running state of the VM was lost when the ESX server failed meaning
the service will be unavailable until the VM has restarted elsewhere.
Although comparing a planned application mobility event to an
unplanned disaster restart will result in the same outcome (i.e., a
service relocating elsewhere) it can now be seen that there is a big
difference since the planned mobility job keeps the application online
during the relocation whereas the disaster restart will result in the
application being offline during the relocation as a restart is
conducted.
Compared to active/active technologies the use of legacy
active/passive type solutions in these restart scenarios would
typically require an extra step over and above standard application
failover since a storage failover would also be required (i.e. changing
the status of write disabled remote copy to read/write and reversing
replication direction flow). This is where VPLEX can assist greatly
since it is active/active therefore, in most cases, no manual
intervention at the storage layer is required, this greatly reduces the
complexity of a DR failover solution. If best practices for physical
high available and redundant hardware connectivity are followed the
value of VPLEX Witness will truly provide customers with
“Absolute” availability!
30 EMC VPLEX Metro Witness Technology and High Availability
31. 2
Hardware and Software
This chapter provides insight into the hardware and software
interfaces that can be used by an administrator to manage all aspects
of a VPLEX system. In addition, a brief overview of the internal
system software is included. Topics include:
◆ Introduction ........................................................................................ 32
◆ VPLEX management interfaces........................................................ 37
◆ Simplified storage management ...................................................... 39
◆ Management server user accounts .................................................. 40
◆ Management server software ........................................................... 41
◆ Director software................................................................................ 45
◆ Configuration overview.................................................................... 46
◆ I/O implementation .......................................................................... 50
Hardware and Software 31
32. Hardware and Software
Introduction
This section provides basic information on the following:
◆ “VPLEX I/O” on page 32
◆ “High-level VPLEX I/O flow” on page 32
◆ “Distributed coherent cache” on page 33
◆ “VPLEX family clustering architecture ” on page 33
VPLEX I/O
VPLEX is built on a lightweight protocol that maintains cache
coherency for storage I/O and the VPLEX cluster provides highly
available cache, processing power, front-end, and back-end Fibre
Channel interfaces.
EMC hardware powers the VPLEX cluster design so that all devices
are always available and I/O that enters the cluster from anywhere
can be serviced by any node within the cluster.
The AccessAnywhere feature in the VPLEX Metro and VPLEX Geo
products extends the cache coherency between data centers at a
distance.
High-level VPLEX I/O flow
VPLEX abstracts a block-level ownership model into a highly
organized hierarchal directory structure that is updated for every I/O
and shared across all engines. The directory uses a small amount of
metadata and tells all other engines in the cluster, in 4k block
transmissions, which block of data is owned by which engine and at
what time.
After a write completes and ownership is reflected in the directory,
VPLEX dynamically manages read requests for the completed write
in the most efficient way possible.
When a read request arrives, VPLEX checks the directory for an
owner. After VPLEX locates the owner, the read request goes directly
to that engine.
32 EMC VPLEX Metro Witness Technology and High Availability
33. Hardware and Software
On reads from other engines, VPLEX checks the directory and tries to
pull the read I/O directly from the engine cache to avoid going to the
physical arrays to satisfy the read.
This model enables VPLEX to stretch the cluster as VPLEX distributes
the directory between clusters and sites. Due to the Hierarchical
nature of the VPLEX directory VPLEX is efficient with minimal
overhead and enables I/O communication over distance.
Distributed coherent cache
The VPLEX engine includes two directors that each have a total of 36
GB (version 5 hardware, also known as VS2) of local cache. Cache
pages are keyed by volume and go through a lifecycle from staging,
to visible, to draining.
The global cache is a combination of all director caches that spans all
clusters. The cache page holder information is maintained in a
memory data structure called a directory.
The directory is divided into chunks and distributed among the
VPLEX directors and locality controls where ownership is
maintained.
A meta-directory identifies which director owns which directory
chunks within the global directory.
VPLEX family clustering architecture
The VPLEX family uses a unique clustering architecture to help
customers break the boundaries of the data center and allow servers
at multiple data centers to have read/write access to shared block
storage devices. A VPLEX cluster, as shown in Figure 6 on page 34,
can scale up through the addition of more engines, and scale out by
connecting clusters into an EMC VPLEX Metro (two VPLEX Metro
clusters connected within Metro distances).
Introduction 33
34. Hardware and Software
Figure 6 VPLEX cluster example
VPLEX Metro transparently moves and shares workloads for a
variety of applications, VMs, databases and cluster file systems.
VPLEX Metro consolidates data centers, and optimizes resource
utilization across data centers. In addition, it provides non-disruptive
data mobility, heterogeneous storage management, and improved
application availability. VPLEX Metro supports up to two clusters,
which can be in the same data center, or at two different sites within
synchronous environments. Also, introduced with these solutions
architected by this TechBook, Geo cluster across distances achieves
the asynchronous partner to Metro. It is out of the scope of this
document to analyze VPLEX Geo capabilities.
34 EMC VPLEX Metro Witness Technology and High Availability
35. Hardware and Software
VPLEX single, dual, and quad engines
The VPLEX engine provides cache and processing power with
redundant directors that each include two I/O modules per director
and one optional WAN COM I/O module for use in VPLEX Metro
and VPLEX Geo configurations.
The rackable hardware components are shipped in NEMA standard
racks or provided, as an option, as a field rackable product. Table 2
provides a list of configurations.
Table 2 Configurations at a glance
Components Single engine Dual engine Quad engine
Directors 2 4 8
Redundant Engine SPSs Yes Yes Yes
FE Fibre Channel ports (VS1) 16 32 64
FE Fibre Channel ports (VS2) 8 16 32
BE Fibre Channel ports (VS1) 16 32 64
BE Fibre Channel ports (VS2) 8 16 32
Cache size (VS1 Hardware) 64 GB 128 GB 256 GB
Cache size (VS2 Hardware) 72 GB 144 GB 288 GB
Management Servers 1 1 1
Internal Fibre Channel switches (Local Comm) None 2 2
Uninterruptable Power Supplies (UPSs) None 2 2
VPLEX sizing tool
Use the EMC VPLEX sizing tool provided by EMC Global Services
Software Development to configure the right VPLEX cluster
configuration.
The sizing tool concentrates on I/O throughput requirement for
installed applications (mail exchange, OLTP, data warehouse, video
streaming, etc.) and back-end configuration such as virtual volumes,
size and quantity of storage volumes, and initiators.
Introduction 35
36. Hardware and Software
Upgrade paths
VPLEX facilitates application and storage upgrades without a service
window through its flexibility to shift production workloads
throughout the VPLEX technology.
In addition, high-availability features of the VPLEX cluster allow for
non-disruptive VPLEX hardware and software upgrades.
This flexibility means that VPLEX is always servicing I/O and never
has to be completely shut down.
Hardware upgrades
Upgrades are supported for single-engine VPLEX systems to dual- or
quad-engine systems.
A single VPLEX Local system can be reconfigured to work as a
VPLEX Metro or VPLEX Geo by adding a new remote VPLEX cluster.
Additionally an entire VPLEX VS1 Cluster (hardware) can be fully
upgraded to VS2 hardware non disruptively.
Information for VPLEX hardware upgrades is in the Procedure
Generator that is available through EMC PowerLink.
Software upgrades
VPLEX features a robust non-disruptive upgrade (NDU) technology
to upgrade the software on VPLEX engines and VPLEX Witness
servers. Management server software must be upgraded before
running the NDU.
Due to the VPLEX distributed coherent cache, directors elsewhere in
the VPLEX installation service I/Os while the upgrade is taking
place. This alleviates the need for service windows and reduces RTO.
The NDU includes the following steps:
◆ Preparing the VPLEX system for the NDU
◆ Starting the NDU
◆ Transferring the I/O to an upgraded director
◆ Completing the NDU
36 EMC VPLEX Metro Witness Technology and High Availability
37. Hardware and Software
VPLEX management interfaces
Within the VPLEX cluster, TCP/IP-based management traffic travels
through a private network subnet to the components in one or more
clusters. In VPLEX Metro and VPLEX Geo, VPLEX establishes a VPN
tunnel between the management servers of both clusters. When
VPLEX Witness is deployed, the VPN tunnel is extended to a 3-way
tunnel including both Management Servers and VPLEX Witness.
Web-based GUI
VPLEX includes a Web-based graphical user interface (GUI) for
management. The EMC VPLEX Management Console Help provides
more information on using this interface.
To perform other VPLEX operations that are not available in the GUI,
refer to the CLI, which supports full functionality. The EMC VPLEX
CLI Guide provides a comprehensive list of VPLEX commands and
detailed instructions on using those commands.
The EMC VPLEX Management Console contains but is not limited to
the following functions:
◆ Supports storage array discovery and provisioning
◆ Local provisioning
◆ Distributed provisioning
◆ Mobility Central
◆ Online help
VPLEX CLI
VPlexcli is a command line interface (CLI) to configure and operate
VPLEX systems. It also generates the EZ Wizard Setup process to
make installation of VPLEX easier and quicker.
The CLI is divided into command contexts. Some commands are
accessible from all contexts, and are referred to as ‘global commands’.
The remaining commands are arranged in a hierarchical context tree
that can only be executed from the appropriate location in the context
tree.
VPLEX management interfaces 37
38. Hardware and Software
The VPlexcli encompasses all capabilities in order to function if the
management station is unavailable. It is fully functional,
comprehensive, supporting full configuration, provisioning and
advanced systems management capabilities.
SNMP support for performance statistics
The VPLEX snmpv2c SNMP agent:
◆ Supports retrieval of performance-related statistics as published
in the VPLEX-MIB.mib.
◆ Runs on the management server and fetches performance related
data from individual directors using a firmware specific
interface.
◆ Provides SNMP MIB data for directors for the local cluster only.
LDAP /AD support
VPLEX offers Lightweight Directory Access Protocol (LDAP) or
Active Directory for an authentication directory service.
VPLEX Element Manager API
VPLEX Element Manager API uses the Representational State
Transfer (REST) software architecture for distributed systems such as
the World Wide Web. It allows software developers and other users to
use the API to create scripts to run VPLEX CLI commands.
The VPLEX Element Manager API supports all VPLEX CLI
commands that can be executed from the root context on a director.
38 EMC VPLEX Metro Witness Technology and High Availability
39. Hardware and Software
Simplified storage management
VPLEX supports a variety of arrays from various vendors covering
both active/active and active/passive type arrays. VPLEX simplifies
storage management by allowing simple LUNs, provisioned from the
various arrays, to be managed through a centralized management
interface that is simple to use and very intuitive. In addition, a
VPLEX Metro or VPLEX Geo environment that spans data centers
allows the storage administrator to manage both locations through
the one interface from either location by logging in at the local site.
Simplified storage management 39
40. Hardware and Software
Management server user accounts
The management server requires the setup of user accounts for access
to certain tasks. Table 3 describes the types of user accounts on the
management server.
Table 3 Management server user accounts
Account type Purpose
admin (customer) • Performs administrative actions, such as user
management
• Creates and deletes Linux CLI accounts
• Resets passwords for all Linux CLI users
• Modifies the public Ethernet settings
service • Starts and stops necessary OS and VPLEX services
(EMC service) • Cannot modify user accounts
• (Customers do have access to this account)
Linux CLI accounts • Uses VPlexcli to manage federated storage
All account types • Uses VPlexcli
• Modifies their own password
• Can SSH or VNC into the management server
• Can SCP files off the management server from directories
to which they have access
Some service and administrator tasks require OS commands that
require root privileges. The management server has been configured
to use the sudo program to provide these root privileges just for the
duration of the command. Sudo is a secure and well-established
UNIX program for allowing users to run commands with root
privileges.
VPLEX documentation will indicate which commands must be
prefixed with "sudo" in order to acquire the necessary privileges. The
sudo command will ask for the user's password when it runs for the
first time, to ensure that the user knows the password for his account.
This prevents unauthorized users from executing these privileged
commands when they find an authenticated SSH login that was left
open.
40 EMC VPLEX Metro Witness Technology and High Availability
41. Hardware and Software
Management server software
The management server software is installed during manufacturing
and is fully field upgradeable. The software includes:
◆ VPLEX Management Console
◆ VPlexcli
◆ Server Base Image Updates (when necessary)
◆ Call-home software
Each are briefly discussed in this section.
Management console
The VPLEX Management Console provides a graphical user interface
(GUI) to manage the VPLEX cluster. The GUI can be used to
provision storage, as well as manage and monitor system
performance.
Figure 7 on page 42 shows the VPLEX Management Console window
with the cluster tree expanded to show the objects that are
manageable from the front-end, back-end, and the federated storage.
Management server software 41
42. Hardware and Software
Figure 7 VPLEX Management Console
The VPLEX Management Console provides online help for all of its
available functions. Online help can be accessed in the following
ways:
◆ Click the Help icon in the upper right corner on the main screen
to open the online help system, or in a specific screen to open a
topic specific to the current task.
◆ Click the Help button on the task bar to display a list of links to
additional VPLEX documentation and other sources of
information.
42 EMC VPLEX Metro Witness Technology and High Availability
43. Hardware and Software
Figure 8 is the welcome screen of the VPLEX Management Console
GUI, which utilizes a secure http connection via a browser. The
interface uses Flash technology for rapid response and unique look
and feel.
Figure 8 Management Console welcome screen
Command line interface
The VPlexcli is a command line interface (CLI) for configuring and
running the VPLEX system, for setting up and monitoring the
system’s hardware and intersite links (including com/tcp), and for
configuring global inter-site I/O cost and link-failure recovery. The
CLI runs as a service on the VPLEX management server and is
accessible using Secure Shell (SSH).
Management server software 43
44. Hardware and Software
For information about the VPlexcli, refer to the EMC VPLEX CLI
Guide.
System reporting
VPLEX system reporting software collects configuration information
from each cluster and each engine. The resulting configuration file
(XML) is zipped and stored locally on the management server or
presented to the SYR system at EMC via call home.
You can schedule a weekly job to automatically collect SYR data
(VPlexcli command scheduleSYR), or manually collect it whenever
needed (VPlexcli command syrcollect).
44 EMC VPLEX Metro Witness Technology and High Availability
45. Hardware and Software
Director software
The director software provides:
◆ Basic Input/Output System (BIOS ) — Provides low-level
hardware support to the operating system, and maintains boot
configuration.
◆ Power-On Self Test (POST) — Provides automated testing of
system hardware during power on.
◆ Linux — Provides basic operating system services to the Vplexcli
software stack running on the directors.
◆ VPLEX Power and Environmental Monitoring (ZPEM) —
Provides monitoring and reporting of system hardware status.
◆ EMC Common Object Model (ECOM) —Provides management
logic and interfaces to the internal components of the system.
◆ Log server — Collates log messages from director processes and
sends them to the SMS.
◆ EMC GeoSynchrony™ (I/O Stack) — Processes I/O from hosts,
performs all cache processing, replication, and virtualization
logic, interfaces with arrays for claiming and I/O.
Director software 45
46. Hardware and Software
Configuration overview
The VPLEX configurations are based on how many engines are in the
cabinet. The basic configurations are single, dual and quad
(previously know as small, medium and large).
The configuration sizes refer to the number of engines in the VPLEX
cabinet. The remainder of this section describes each configuration
size.
Single engine configurations
The VPLEX single engine configuration includes the following:
◆ Two directors
◆ One engine
◆ Redundant engine SPSs
◆ 8 front-end Fibre Channel ports (16 for VS1 hardware)
◆ 8 back-end Fibre Channel ports (16 for VS1 hardware)
◆ One management server
The unused space between engine 1 and the management server as
shown in Figure 9 on page 47 is intentional.
46 EMC VPLEX Metro Witness Technology and High Availability
47. Hardware and Software
Figure 9 VPLEX single engine configuration
Dual configurations
The VPLEX dual engine configuration includes the following:
◆ Four directors
◆ Two engines
◆ Redundant engine SPSs
◆ 16 front-end Fibre Channel ports (32 for VS1 hardware)
◆ 16 back-end Fibre Channel ports (32 for VS1 hardware)
◆ One management server
Configuration overview 47
48. Hardware and Software
◆ Redundant Fibre Channel COM switches for local COM; UPS for
each Fibre Channel switch
Figure 10 shows an example of a medium configuration.
ON ON
I I
O O
OFF OFF
ON ON
I I
O O
OFF OFF
ON ON
I I
O O
OFF OFF
Fibre Channel switch B
UPS B
Fibre Channel switch A
UPS A
OFF OFF
O O
I I
ON ON
Management server
Engine 2
OFF OFF
O O
I I
ON ON
SPS 2
OFF OFF
O O
I I
ON ON
Engine 1
SPS 1
VPLX-000254
Figure 10 VPLEX dual engine configuration
Quad configurations
The VPLEX quad engine configuration includes the following:
◆ Eight directors
◆ Four engines
◆ Redundant engine SPSs
◆ 32 front-end Fibre Channel ports (64 for VS1 hardware)
48 EMC VPLEX Metro Witness Technology and High Availability
49. Hardware and Software
◆ 32 back-end Fibre Channel ports (64 for VS1 hardware)
◆ One management server
◆ Redundant Fibre Channel COM switches for local COM; UPS for
each Fibre Channel switch
Figure 11 shows an example of a quad configuration.
ON
I
O
ON
I
O
Engine 4
OFF OFF
SPS 4
ON ON
I I
O O
OFF OFF
Engine 3
ON ON
I I
O O
OFF OFF
SPS 3
Fibre Channel switch B
UPS B
Fibre Channel switch A
UPS A
OFF OFF
O O
I I
ON ON
Management server
Engine 2
OFF OFF
O O
I I
ON ON
SPS 2
OFF OFF
O O
I I
ON ON
Engine 1
SPS 1
VPLX 000253
Figure 11 VPLEX quad engine configuration
Configuration overview 49
50. Hardware and Software
I/O implementation
The VPLEX cluster utilizes a write-through mode when configured
for either VPLEX Local or Metro whereby all writes are written
through the cache to the back-end storage. To maintain data integrity,
a host write is acknowledged only after the back-end arrays (in one
cluster in case of VPLEX Local and in two clusters in case of VPLEX
Metro) acknowledge the write.
This section describes the VPLEX cluster caching layers, roles, and
interactions. It gives an overview of how reads and writes are
handled within the VPLEX cluster and how distributed cache
coherency works. This is important to the introduction of high
availability concepts.
Cache coherence
Cache coherence creates a consistent global view of a volume.
Distributed cache coherence is maintained using a directory. There is
one directory per virtual volume and each directory is split into
chunks (4096 directory entries within each). These chunks exist only
if they are populated. There is one directory entry per global cache
page, with responsibility for:
◆ Tracking page owner(s) and remembering the last writer
◆ Locking and queuing
Meta-directory
Directory chunks are managed by the meta-directory, which assigns
and remembers chunk ownership. These chunks can migrate using
Locality-Conscious Directory Migration (LCDM). This
meta-directory knowledge is cached across the share group (i.e., a
group of multiple directors within the cluster that are exporting a
given virtual volume) for efficiency.
How a read is handled
When a host makes a read request, VPLEX first searches its local
cache. If the data is found there, it is returned to the host.
50 EMC VPLEX Metro Witness Technology and High Availability
51. Hardware and Software
If the data is not found in local cache, VPLEX searches global cache.
Global cache includes all directors that are connected to one another
within the single VPLEX cluster for VPLEX Local, and all of the
VPLEX clusters for both VPLEX Metro and VPLEX Geo. If there is a
global read hit in the local cluster (i.e. same cluster, but different
director) then the read will be serviced from global cache in the same
cluster. The read could also be serviced by the remote global cache if
the consistency group setting “local read override” is set to false (the
default is true). Whenever the read is serviced from global cache
(same cluster or remote), a copy is also stored in the local cache of the
director from where the request originated.
If a read cannot be serviced from either local cache or global cache, it
is read directly from the back-end storage. In these cases both the
global and local cache are updated.
I/O flow of a local read hit
1. Read request issued to virtual volume from host.
2. Look up in local cache of ingress director.
3. On hit, data returned from local cache to host.
I/O flow of a global read hit
1. Read request issued to virtual volume from host.
2. Look up in local cache of ingress director.
3. On miss, look up in global cache.
4. On hit, data is copied from owner director into local cache.
5. Data returned from local cache to host.
I/O flow of a read miss
1. Read request issued to virtual volume from host.
2. Look up in local cache of ingress director.
3. On miss, look up in global cache.
4. On miss, data read from storage volume into local cache.
5. Data returned from local cache to host.
6. The director that returned the data becomes the chunk owner.
I/O implementation 51