The use of VDI (Virtual Desktop Infrastructure) enables enterprises to become more agile and flexible, in tune with the needs of today’s mobile-powered workforce. Users can access their desktop, data, and applications from any location, without being tied to a single device. The centralized client environment is easier for IT to manage and maintain, enabling faster response to the changing needs of both users and business.
However, because these virtual desktops run on a Hypervisor, which in turn runs on disks managed by a storage device/control-ler, underlying storage can easily become a performance bottleneck. For this reason, storage is a significant component for any VDI deployment and can cost organizations as much as seven times the cost of the VDI deployment itself.
VDI implementation thus presents formidable challenges of storage performance and escalating costs due to the increased storage requirements. It is also a storage management challenge.
CLOUDBYTE™ ELASTISTOR™ QOS GUARANTEE MEETS USER REQUIREMENTS
WHILE REDUCING TCO
THE VDI STORAGE CHALLENGE
When hundreds of desktops are consolidated on a single storage network, traditional storage systems struggle for several key reasons:
These issues arise because traditional storage tends to deal in predictable, sequential demands for data with a read/write ratio of 80:20. VDI deployments, on the other hand, exhibit largely random I/O requests and can easily reach read/write ratios of 50:50 or more.
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Input/output operations per second (IOPS) fast become very high•
When a significant number of end users boot up within a short period of time, for example at shift changes, the resulting “boot storm” overwhelms the network and causes significant performance degradation•
Critical updates and patches can disrupt the flow of data across the system•
User demands on the system are unpredictable and tend to cause small random I/O bursts•
The larger the number of users, the greater the likely impact of all the above factors•
Adding hardware capacity does not necessarily solve the problem2
MEETING THE CHALLENGE
Powered by patented “Tenant Storage Machine” architecture with guaranteed QoS, CloudByte ElastiStor delivers a cost effective and efficient solution to the challenges of storage in VDI environments:
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Intelligent caching minimizes the impact of boot storms•
QoS guarantee meets performance require ments of different users/ applicationsA typical CloudByte deployment establishes ElastiStor as an operating environment on qualified industry standard servers. These servers then act as individual storage nodes, which can be configured in High Availability mode. Storage is provisioned from the storage node through FC/CIFS/NFS/iSCSI to the Hypervisor servers. The ElastiStor QoS promise operates at the GUI level, enabling IOPS for even the most demanding users and applications to be guaranteed.
As shown on the next page, the ElastiStor storage OS is installed on industry standard commodity servers, which become storage controllers. Depending on capacity requirements, disks can be added to the controllers through SAS switches.
SOLUTION ARCHITECTURE
This flexible architecture ensures that ElastiStor deployments can be scaled seamlessly in line with increases in numbers of VDI users.
HOW DOES ELASTISTOR HELP?
CloudByte ElastiStor’s QoS promise guarantees IOPS and throughput to meet the requirements of the most demanding users and applications under VDI.
With traditional storage systems, the storage amount needed is equal to the sum of the storage required by each guest OS. ElastiStor’s cloning, deduplication, compression, and thin provisioning ensure an effective reduction in overall physical storage demands.
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When Solid State Drives (SSDs) are added to a storage pool, the ZFS Intent log (ZIL) speeds write capabilities•
The use of SSDs for caching reads manages the potential performance impact of boot storms•
SSD-based (ZIL) write caching improves synchronous I/O’s•
Inline compression reduces I/O for compressible data.•
Support for variable block sizes ensures performance optimization by matching application record sizes, which also helps to improve performance under diverse workloads.CUSTOM-DESIGNED FOR VDI
• ElastiStor’s SSD-based ZFS intent log (ZIL)
write caching speeds up write capabilities, improving synchronous I/O.•
Cloning, deduplication, compression, and thin provisioning ensure a significant reduction in overall physical storage requirements• The ElastiStor storage operating system is
installed on industry standard commodity servers, which then become storage controllers.•
Boot drives are cloned and ElastiStor’s inline deduplication delivers significant savings in storage space requirementsCloudByte recommends adding a middle cache tier to significantly improve performance, an approach not possible with tradi-tional storage systems, which follow a direct RAM-to-DISK operation.
The Adaptive Replacement Cache (ARC) resides in RAM and is the first destination for all data written to a ZFS Pool and is the fastest source for data READs from the pool. When data is requested from ZFS, it first looks in the ARC; if data is present, it can quickly be retrieved by the application. The contents of the ARC are balanced between the most recently used (MRU) and the most frequently used (MFU) data. The second level (L2) cache resides in SSD and is populated by data first placed in the ARC.
The amount of RAM needed for L2ARC varies according to individual requirements, but for example, about 15 GB of RAM is required to reference 600 GB of L2ARC at an 8 KB ZFS record size. For a 16 KB record size, the RAM required is halved to 7.5 GB. If insufficient RAM is configured, L2ARC will not completely populate with the MRU and MFU data. CloudByte ElastiStor is a highly available and completely redundant systemat all levels
CACHE SIZING FOR OPTIMAL PERFORMANCE
RAM
ZIL L2ARC
DISKS
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N-way availability at the ElastiStor level•
Redundant SAS switch connectivity•
Disk array failure tolerance•
Dual power supplyVirtual machine boot drives and application data drives are created from storage provisioned by ElastiStor.
CloudByte delivers the most cost-effective storage solution for VDI environments and removes the limitations of legacy hardware-based storage solutions by:
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Adapting storage system resources to the requirements of VDI through the performance QoS provided to all storage end points•
Controlling the volume of random IOPS by buffering writeIN SUMMARY
“Designed for virtualized environments, CloudByte ElastiStor redefines storage endpoints beyond capacity to storage performance (IOPS, throughput, and latency). Applications with diverse workloads can now be hosted with guaranteed performance on a single extensible shared storage platform, resulting in cost savings of 80-90% (vs. legacy solutions which require fragmented storage islands).
“With CloudByte, storage management is also dramatically simplified with ondemand provisioning, multi-node management, and powerful REST APIs.”
CLOUDBYTE ECOSYSTEM
TM
C L O U D S O F T W A R E
Integrated with
READY
application. Established in 2011 by technology executives from companies such as HP, IBM, NetApp, and Novell, CloudByte is backed by Fidelity Worldwide Investment, Nexus Venture Partners and Kae Capital.
