A distributed file system (DFS) allows storage and access of files across networked computers. It employs concepts like transparency, caching, replication and access control to provide a coherent view of files. A DFS consists of directory services to look up file locations, authorization services to control access, file services to read/write files and system services for device and block management. Files can be organized hierarchically with directories and accessed using pathnames. Version control separates enforcing sharing semantics from file services by labeling file revisions with version numbers.
The impact of innovation on travel and tourism industries (World Travel Marke...Brian Solis
From the impact of Pokemon Go on Silicon Valley to artificial intelligence, futurist Brian Solis talks to Mathew Parsons of World Travel Market about the future of travel, tourism and hospitality.
The Six Highest Performing B2B Blog Post FormatsBarry Feldman
If your B2B blogging goals include earning social media shares and backlinks to boost your search rankings, this infographic lists the size best approaches.
Each technological age has been marked by a shift in how the industrial platform enables companies to rethink their business processes and create wealth. In the talk I argue that we are limiting our view of what this next industrial/digital age can offer because of how we read, measure and through that perceive the world (how we cherry pick data). Companies are locked in metrics and quantitative measures, data that can fit into a spreadsheet. And by that they see the digital transformation merely as an efficiency tool to the fossil fuel age. But we need to stretch further…
In computing, a distributed file system (DFS) or network file system is any file system that allows access to files from multiple hosts sharing via a computer network. This makes it possible for multiple users on multiple machines to share files and storage resources.
A workshop hosted by the South African Journal of Science aimed at postgraduate students and early career researchers with little or no experience in writing and publishing journal articles.
June 3, 2024 Anti-Semitism Letter Sent to MIT President Kornbluth and MIT Cor...Levi Shapiro
Letter from the Congress of the United States regarding Anti-Semitism sent June 3rd to MIT President Sally Kornbluth, MIT Corp Chair, Mark Gorenberg
Dear Dr. Kornbluth and Mr. Gorenberg,
The US House of Representatives is deeply concerned by ongoing and pervasive acts of antisemitic
harassment and intimidation at the Massachusetts Institute of Technology (MIT). Failing to act decisively to ensure a safe learning environment for all students would be a grave dereliction of your responsibilities as President of MIT and Chair of the MIT Corporation.
This Congress will not stand idly by and allow an environment hostile to Jewish students to persist. The House believes that your institution is in violation of Title VI of the Civil Rights Act, and the inability or
unwillingness to rectify this violation through action requires accountability.
Postsecondary education is a unique opportunity for students to learn and have their ideas and beliefs challenged. However, universities receiving hundreds of millions of federal funds annually have denied
students that opportunity and have been hijacked to become venues for the promotion of terrorism, antisemitic harassment and intimidation, unlawful encampments, and in some cases, assaults and riots.
The House of Representatives will not countenance the use of federal funds to indoctrinate students into hateful, antisemitic, anti-American supporters of terrorism. Investigations into campus antisemitism by the Committee on Education and the Workforce and the Committee on Ways and Means have been expanded into a Congress-wide probe across all relevant jurisdictions to address this national crisis. The undersigned Committees will conduct oversight into the use of federal funds at MIT and its learning environment under authorities granted to each Committee.
• The Committee on Education and the Workforce has been investigating your institution since December 7, 2023. The Committee has broad jurisdiction over postsecondary education, including its compliance with Title VI of the Civil Rights Act, campus safety concerns over disruptions to the learning environment, and the awarding of federal student aid under the Higher Education Act.
• The Committee on Oversight and Accountability is investigating the sources of funding and other support flowing to groups espousing pro-Hamas propaganda and engaged in antisemitic harassment and intimidation of students. The Committee on Oversight and Accountability is the principal oversight committee of the US House of Representatives and has broad authority to investigate “any matter” at “any time” under House Rule X.
• The Committee on Ways and Means has been investigating several universities since November 15, 2023, when the Committee held a hearing entitled From Ivory Towers to Dark Corners: Investigating the Nexus Between Antisemitism, Tax-Exempt Universities, and Terror Financing. The Committee followed the hearing with letters to those institutions on January 10, 202
Acetabularia Information For Class 9 .docxvaibhavrinwa19
Acetabularia acetabulum is a single-celled green alga that in its vegetative state is morphologically differentiated into a basal rhizoid and an axially elongated stalk, which bears whorls of branching hairs. The single diploid nucleus resides in the rhizoid.
How to Add Chatter in the odoo 17 ERP ModuleCeline George
In Odoo, the chatter is like a chat tool that helps you work together on records. You can leave notes and track things, making it easier to talk with your team and partners. Inside chatter, all communication history, activity, and changes will be displayed.
Safalta Digital marketing institute in Noida, provide complete applications that encompass a huge range of virtual advertising and marketing additives, which includes search engine optimization, virtual communication advertising, pay-per-click on marketing, content material advertising, internet analytics, and greater. These university courses are designed for students who possess a comprehensive understanding of virtual marketing strategies and attributes.Safalta Digital Marketing Institute in Noida is a first choice for young individuals or students who are looking to start their careers in the field of digital advertising. The institute gives specialized courses designed and certification.
for beginners, providing thorough training in areas such as SEO, digital communication marketing, and PPC training in Noida. After finishing the program, students receive the certifications recognised by top different universitie, setting a strong foundation for a successful career in digital marketing.
This presentation includes basic of PCOS their pathology and treatment and also Ayurveda correlation of PCOS and Ayurvedic line of treatment mentioned in classics.
The simplified electron and muon model, Oscillating Spacetime: The Foundation...RitikBhardwaj56
Discover the Simplified Electron and Muon Model: A New Wave-Based Approach to Understanding Particles delves into a groundbreaking theory that presents electrons and muons as rotating soliton waves within oscillating spacetime. Geared towards students, researchers, and science buffs, this book breaks down complex ideas into simple explanations. It covers topics such as electron waves, temporal dynamics, and the implications of this model on particle physics. With clear illustrations and easy-to-follow explanations, readers will gain a new outlook on the universe's fundamental nature.
2024.06.01 Introducing a competency framework for languag learning materials ...Sandy Millin
http://sandymillin.wordpress.com/iateflwebinar2024
Published classroom materials form the basis of syllabuses, drive teacher professional development, and have a potentially huge influence on learners, teachers and education systems. All teachers also create their own materials, whether a few sentences on a blackboard, a highly-structured fully-realised online course, or anything in between. Despite this, the knowledge and skills needed to create effective language learning materials are rarely part of teacher training, and are mostly learnt by trial and error.
Knowledge and skills frameworks, generally called competency frameworks, for ELT teachers, trainers and managers have existed for a few years now. However, until I created one for my MA dissertation, there wasn’t one drawing together what we need to know and do to be able to effectively produce language learning materials.
This webinar will introduce you to my framework, highlighting the key competencies I identified from my research. It will also show how anybody involved in language teaching (any language, not just English!), teacher training, managing schools or developing language learning materials can benefit from using the framework.
How to Build a Module in Odoo 17 Using the Scaffold MethodCeline George
Odoo provides an option for creating a module by using a single line command. By using this command the user can make a whole structure of a module. It is very easy for a beginner to make a module. There is no need to make each file manually. This slide will show how to create a module using the scaffold method.
2. Computing System is a collection of processes
operating on data objects.
Persistent data objects should be named and saved
on nonvolatile storage device.
Named data objects are files.
A file system is a major component in an OS.
A Distributed File System(DFS) is an
implementation of file system.
3. Important concepts in distributed System
design
• DFSs employ many aspects of the notion of
transparency.
• The directory service in DFS is a key
component in all distributed systems.
• The performance and availability require the
use of caching and replication.
• Access control and protection for DFSs open
many problems in distributed system security.
4. Characteristics of DFS:
dispersion and multiplicity of users and files.
Transparent DFS should exhibit the following properties:
Dispersed Clients
Dispersed Files
Multiplicity of users
Multiplicity of files
5. DFS DESIGN AND IMPLEMENTATION
Basic concepts of files and file systems:
Files consists of three logical components.
File
attributes
Data unitsFile name
File accesses are generally in one of the three modes:
Sequential access, Direct access , indexed sequential
access.
6. A file system consists of four major components:
I. Directory
II. Authorization
III. File service
IV. System services
Directory service Name resolution, add &
deletion of files
Authorization service Capability and/or access
control list
File service Transaction Concurrency & replication
management
basic read./write files and get/set
attributes
System services Device, cache and block
mgmt
7. The organization of data files can be either flat or
hierarchical.
Files are named and accessed using a hierarchical pathname .
root
chow johnson
report
book Paper
Directories are files that contain names and
addresses of other files and subdirectories.
8. File access must be regulated to ensure security.
Directory , Authorization and file services are user
interfaces to a file system.
System services are file systems interface to hardware & are
transparent to users.
Major Fns of System services includes:
• mapping of logical to physical block addresses
• Interfacing to services at the device level for file
space allocation/deallocation
• Actual read/write file operations.
9. Services and Servers:
Servers are processes that implement services.
A service may be implemented by a server/ number of servers.
A server may also provide multiple services.
Interaction among services in DFS:
Directory
service
Authorization
service
File service
System
service
Servers
clients
10. File mounting and Server Registration
Constructs a large file system from various file servers and
storage devices
Mounting point is usually the leaf of directory tree that
contain only an empty subdirectory
Once files are mounted they’re accessed using the
concatenated logical path names.
File system mounting can be done in three diff instances:
o Explicit mounting
o Boot mounting
o Auto mounting
11. Stateful and Stateless File Servers
A connection requires the establishment and termination
of communication session. There’s state information
associated with each session.
Ex:
Opened files and their clients
File descriptors and File handles
Current file position pointers
Mounting information
Lock status
Session keys
Cache/Buffer
12. A file server is stateful if it maintains internally some of the
state information and stateless if it maintains none at all.
Implementation of stateless server must address the following
issues:
Idempotency Requirement
File locking mechanism
Session key management
Cache consistency
13. File Access and Semantics of sharing
File sharing- multiple clients access same file at same time.
The may result from either
overlapping/interleaving
Coherency Control- Managing access to the replicas, to
provide a coherent view of the shared file
Concurrency control- Concurrency is achieved by time
multiplexing of the files and the issues here are how to
prevent one execution sequence from interfering with others
when they’re interleaved & how to avoid inconsistent results.
14. In space domain read and write accesses to a remote file can be implemented in
one of the following ways:
1.Remote access
2.Cache access
3.Download/upload access
Coherency of replicated data may be interpreted in many diff ways
1. All replicas are identical in all times
2. Replicas are perceived as identical only at some points in time
3. Users always read the “most recent”data in the replicas.
4. Write operations are always performed immediately and their results
are propagated in a best -effort fashion
In time domain interleaved read and write results in concurrent file accesses.
1. Simple RW
2. Transaction
3. Session
15. Semantics of sharing
Solutions to coherency and concurrency control problem
depends on semantics of sharing.
Three popular semantic models:
• Unix semantics
• Transaction semantics
• Session semantics
16. Version control:
All problems associated with file sharing and replication
disappear if the file is read only. To achieve write sharing
clients must know the names of newly created files.
A simple solution is to use same file name but with a
version number for each revision of the file.
The burden of enforcing file sharing semantics is
separated from the file service in to a higher level service
called version control.
File with highest version number considered to be current
version.