The document discusses the limitations of legacy storage solutions for cloud service providers hosting performance-sensitive applications. Traditional and advanced storage arrays cannot guarantee quality of service due to "noisy neighbor" issues where applications contend for shared resources. Scale-out storage overcomes noisy neighbors by overprovisioning hardware, but cannot set specific service level agreements for tenants. The document introduces CloudByte ElastiStor as a solution that can guarantee quality of service for each application running on shared storage by resolving noisy neighbor issues through its patented technology.

1. White Paper
For Service Providers
Host Performance-Sensitive Applications in Your Cloud
CloudByte ElastiStor Resolves Noisy Neighbor Issues
and Delivers Guaranteed QoS to Every Application

2. Table of Contents
Executive Summary ………………………………………………………………………………….… 3
Limitations of Legacy Solutions …………….…………………………………………………… 4
ElastiStor Cures Noisy Neighbor Issues ..………………………………………………….… 6
ElastiStor: Key Features …………….……………………..…………………………………………. 7
ElastiStor: Standard Storage Features ………..…………………………………………….… 8
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3. Executive Summary
Business Opportunity for Service Providers
For organizations today, running applications in the cloud has become a matter of “when will we
deploy,” and not “should we deploy.” Even conservative IT shops that may have shied away from
the public cloud have at least embraced the cost and efficiency advantages of deploying utility
computing.
Large “retail-class” infrastructure as a service (IaaS) providers, like Amazon Web Services, work well
for applications that require scaling to high aggregate processing throughput or near-infinite
storage capacity. But, there are significant challenges in hosting performance-sensitive
applications. A significant business opportunity exists for Cloud Service Providers (CSPs) that can
support QoS-sensitive workloads, like Oracle, SAP, SAS, OLTP, ERP, etc.
Challenges in Hosting Performance-Sensitive Applications
Hosting performance-sensitive enterprise applications requires delivery of guaranteed QoS, which
has been the Achilles heel of large cloud service providers. In fact, without much effort, one can
find many horror stories from many organizations trying to get databases running—and keep them
running—in these environments.
So, what stops legacy solutions from delivering guaranteed QoS? Noisy neighbors! Within a shared
storage platform, legacy solutions cannot isolate and dedicate a specific set of resources to any
application. As a result, applications are in a constant struggle for the shared storage resources. An
application’s IOPS, throughput, and latency are determined by the current state of the system (i.e.,
currently available resources), rather than being in sync with its workload characteristics. An
obvious solution is to dedicate physical storage per application. But this implies a huge wastage of
resources and an exorbitant cost structure for the CSP. The only efficient solution is to virtually
isolate applications and dedicate/control resources allotted to them right from the shared storage
platform i.e., provide a true multi-tenant solution.
Legacy storage solutions—traditional SAN/NAS arrays, advanced SAN/NAS arrays, and scale-out
storage platform–fall woefully short of providing a true multi-tenant storage architecture, that is
capable of guaranteeing QoS. With traditional storage arrays, admins typically resort to faster
spindles and more capable controllers. This is both inefficient and difficult to implement as
datacenters scale. Advanced storage arrays provide compartmentalization of tenants (to an extent)
and CoS (control of service). CoS does not guarantee QoS and just gives the admin a way to decide
which workload loses the least during periods when the system gets busy. Scale-out storage
solutions eliminate multiple points of management by building, in effect, a storage cloud to which
controllers and disk can be added and decommissioned with absolutely no impact to tenant
workloads. They are designed around the principle of throwing hardware at the QoS problem,
albeit making the process easier. To conclude, every legacy storage solution resorts to
overprovisioning to workaround the noisy neighbor problem, resulting in a prohibitively expensive
cost structure for CSPs, especially as they scale to hundreds of applications.
CloudByte ElastiStor Guarantees QoS right from Shared Storage
ElastiStor, with its patented TSMTM architecture, is specifically designed for hosting multiple
disparate workloads on a single system. For the first time ever, ElastiStor delivers guaranteed QoS
to every application within shared storage, resolving the noisy neighbor issues. In addition to
industry-first multi-tenant capabilities, ElastiStor provides all the standard storage features that
CSPs need. Software-only and software-defined, CloudByte also frees CSPs from any proprietary
lock-in, eliminating large upfront and ongoing investments.
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4. Limitations of Legacy Solutions
Cloud Service Providers have several options when deploying a shared storage solution. They are:
traditional SAN/NAS arrays, advanced SAN/NAS arrays, and scale-out storage platforms. As we will
see in detail, all these solutions fall short of delivering guaranteed QoS within shared storage.
Traditional Storage Arrays are Designed for Capacity Control
With a traditional SAN/NAS array, CSPs have a single parameter that can be controlled for each
tenant: storage capacity. Disk consumption is clearly important, but in a multi-tenant environment,
the most troublesome issue is performance due to multiple workloads competing for scarce
resources. Unfortunately, standard storage platforms do nothing to help the CSP ensure that each
tenant receives its appropriate share. So, administrators need to design storage systems to ensure
that each workloads will have its required resources when they are needed. Additionally, it is vitally
important to allocate some reserve performance capacity to account for bursts of activity and other
such periods where system resources may become constrained.
When a traditional storage array runs low on resources, administrators can scale it up by upgrading
to larger and/or faster controllers with more, and faster, spindles. But, once a system reaches its
configurable limits, the only option is to deploy additional storage systems. This, of course, creates
more points of management and goes completely opposite of the CSP’s design goal of creating an
efficient, shared infrastructure. Both of these effects increase the CSP’s costs and create potential
customer satisfaction issues: a perfect storm for driving down revenues.
Advanced Storage Arrays Enable CoS (Control of Service); Do Not Deliver QoS
Some storage vendors have realized the limitations of traditional SAN/NAS arrays and have
innovated by providing limited compartmentalization and control of service (CoS) features in their
offerings. In some respects, this is a significant advantage over the capabilities offered by
traditional arrays because it provides better isolation and security. However, it does nothing to help
resolve the noisy neighbor problem. The compartmentalization feature merely makes the process
of moving noisy neighbors off of a busy storage system easier. Administrators are still forced to
overprovision hardware and monitor for contention so that they can jump into action to migrate
troublesome workloads before all tenants hosted on a particular system begin to suffer.
To alleviate some of the problems associated with these troublesome workloads, some vendors
offer Control of Service (CoS) features. Although it sounds similar, CoS is not QoS. Rather than
setting detailed SLA parameters for each tenant, CoS allows an administrator to select from a
limited set of priorities that can be assigned to each tenant. When the platform becomes resource
constrained, it will utilize the priorities to apportion the scarce processing resources in a so-called
fair manner. In short, overall system performance will suffer in this situation and CoS just gives the
admin a way to decide which workload loses the least during periods when the system gets busy.
Legacy Noisy Neighbors: Applications
Storage Solutions Contending for Resources
No QoS Control
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5. Limitations of Legacy Solutions
Scale-Out Storage Overcomes Noisy Neighbors by Overprovisioning
Scale-out storage is one of the hottest topics in the computer industry today. These solutions allow
CSPs to eliminate multiple points of management by building, in effect, a storage cloud to which
controllers and disk can be added and decommissioned with absolutely no impact to tenant
workloads. However, they are designed around the principle of throwing hardware at the problem.
Scale-out storage platforms aggregate hardware resources into a shared pool under a single
management umbrella and then distribute tenant workloads across that pool. Unlike the traditional
or advanced SAN/NAS solutions previously discussed, these platforms significantly reduce the need
for administrators to keep a close watch over system performance or capacity. Since the aggregate
pool is so large, it is highly unlikely for a single workload, or even a handful of workloads, to
completely overwhelm the system. And, when tenant workloads do start to consume too many
resources, they simply grow the pool.
So, what’s the problem? Like their less-capable cousins, traditional and advanced storage arrays,
scale-out storage platforms lack the ability to set specific SLAs for tenant workloads. Therefore,
administrators are still forced to over-provision to keep aggregate performance ahead of the
demands of tenant workloads. Worse yet, end users will see inconsistent performance as each
tenant’s experience is dictated by the current state of the system. This is a zero-sum game for the
CSP because the inability to contain tenants means continually growing the shared storage pool to
meet customer expectations.
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6. ElastiStor Cures Noisy Neighbor Issues
CloudByte TSM Architecture Cures the Noisy Neighbor Issues
The fundamental difference between legacy storage solutions and CloudByte ElastiStor lies in the
storage controller architecture. ElastiStor, with its TSMTM architecture, is specifically designed for
hosting multiple disparate workloads on a single system.
Legacy solutions have a monolithic storage controller architecture, where applications share a
common pool of resources with no reference to QoS requirements. In a CloudByte controller, each
application is fully isolated at all storage stack levels—this isolated environment known as a TSM is
the fundamental unit of CloudByte architecture. With CloudByte’s TSM architecture, a specific set of
controller resources can now be dedicated to each application, without any impact from other
applications within the shared storage.
Read more about CloudByte technology at http://www.cloudbyte.com/products_technology.aspx
ElastiStor Delivers Guaranteed QoS within Shared Storage
While TSM architecture allows each application to be dedicated a specific set of resources,
CloudByte intelligence takes care of provisioning these resources based on QoS demands for the
application—in terms of IOPS, throughput and latency. Admins can now configure storage
endpoints (LUNs) with the required capacity and performance metrics and CloudByte takes care of
the rest. In short, CloudByte ElastiStor delivers guaranteed QoS to each application within shared
storage—an industry first!
With ElastiStor, CSPs can now affordably host performance-sensitive applications right from shared
storage, without resorting to the expensive dedicated storage or overprovisioning workarounds.
CloudByte ElastiStor also boasts of other industry firsts such as on-demand provisioning and
N-way HA, significantly increasing manageability and reliability. In addition, CloudByte provides all
the standard storage features that CSPs need (see more details in page 8).
Software-defined and software-only, CloudByte frees CSPs from any proprietary lock-in and allows
them to custom-build their infrastructure based on their demands, whether it’s SATA, SAS or SSD.
ElastiStor Delivers Tailored QoS to Every Application within Shared Storage
Every storage endpoint is defined in terms of capacity, IOPS, throughput, latency
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7. ElastiStor: Key Features
QoS-Configurable Storage Endpoints
Share your storage and deliver predictable performance to every application.
For the first time ever, ElastiStor allows storage LUNs to be defined beyond
capacity, in terms of IOPS, throughput and latency. This allows applications
with diverse workloads to be guaranteed QoS right from a shared storage
platform. Together with linear scaling, a single extensible shared storage
platform from ElastiStor can now replace legacy solutions’ dedicated storage
islands. By un-fragmenting storage islands and optimally utilizing resources,
ElastiStor steeply cuts down your storage footprint, leading to 80-90% cost
savings over 3-5 years.
On-Demand Storage Provisioning
Do you still manually configure hardware to provision storage for any new
application? Break the need for hardwiring storage with ElastiStor's
on-demand provisioning. Just enter the required SLA/QoS parameters and let
ElastiStor automate node selection and resource allocation for you. ElastiStor
includes an intelligent heuristics daemon which continuously learns the
quantity of various controller resources needed to deliver the required QoS.
vCenter-like Administration Console
ElastiStor makes managing storage as easy as managing VMs, even when as
you scale to hundreds of applications. Storage admins can now comprehen-
sively manage the entire storage cluster, spanning across multiple sites, from
a single web-based console. Further, ElastiStor gives you unprecedented ac-
cess and control over resource usage within shared storage, right down to
the application-level granularity.
REST APIs and Plugins for Easy Integration
Every action performed at ElastiStor admin console translates into a REST
based API call in the backend, enabling admins to fully manage ElastiStor
right from their existing portals. Our plugin for VMware vCenter (also based
on REST API) enables storage management right from the vCenter, right from
setting QoS policies to monitoring resource usage.
N-way High Availability
ElastiStor enables N-way High Availability, exponentially increasing reliability
(mean time to failure), compared to the standard 2-way HA provided by
existing solutions. CloudByte's storage un-fragmentation and its patented
TSM architecture make N-way HA affordable and feasible.
Delegated Administration
A much requested feature from the cloud service providers, delegated ad-
ministration empowers both CSPs and its customers to monitor and control
storage, as necessary. Management privileges vary based on the admin func-
tionality – for example, a super admin can manage the entire storage cluster,
whereas a customer admin can manage just the storage resources allotted to
that particular customer.
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8. ElastiStor: Standard Storage Features
Scalability 128-bit file system
Zettabyte storage capacity
Unlimited file size
Access Protocols NFSv3, NFSv4, CIFS, iSCSI, FC
Storage Connectivity SAS JBODS, iSCSI targets, FC targets
Storage Resilience RAIDZ1, RAIDZ2
Storage Efficiency De-duplication
Compression
Thin provisioning
Backup Efficient Snapshots, Unlimited
Efficient Clones, Unlimited
Tape Backup
Availability N-way high availability (N-way HA)
Partial failure transfer to the available node
Active-Active mode
HA with/without storage redundancy
Disaster Recovery Tenant level disaster recovery
High availability across primary and DR sites
Block level replication
Synchronous mirroring
Asynchronous mirroring
RPO—Last minute
RTO—Few minutes
Data Integrity Protection against silent data corruption
Fixes corrupt block without having to take the file system offline
CloudByte’s file system is built on ZFS and hence, it inherits all the standard ZFS features
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9. multi-tenant storage
Service Providers can now provide full benefits of dedicated
storage to their customers on a shared storage platform
For more information, visit www.cloudbyte.com or follow us on Twitter @CloudByteInc
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