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Whitepaper | October 2014
Using HGST ServerCache™
with Microsoft Hyper-V
Using HGST ServerCache™ with Microsoft Hyper-V
Table of Contents
Introduction
The Virtual Storage Dilemma
What is Cache and Why it Matters
Read Caching (Write-through caching)..............................................................................1
Write-back Caching (persistent)............................................................................................1
HGST ServerCache
Testing Setup
Results
Solution
Standard Architecture................................................................................................................4
Cached Architecture with HGST ServerCache...............................................................4
Conclusion
Using HGST ServerCache™ with Microsoft Hyper-V
Introduction
Microsoft has decided to step into the virtualization in a big way with Hyper-V 2012. The specs are pretty
impressive. The hosts now support 320 Physical Logical Processors and 4TB of RAM . Along with this each
VM can handle 64 vCPUs and 1TB of RAM. These node can handle 1024 VMs each. Pair this with the fact that
64 node cluster is now supported, you are looking at 8,000 VMs in a cluster. This all runs as a simple add-on
to Microsoft Server 2012 and Microsoft Server 2012 R2. This plus many other new features (SMB 3.0, storage
spaces, Data Deduplication, and more ...) make this the time to take a look at Hyper-V as a viable and full
function virtualization infrastructure.
HGST ServerCache provides SSD-level performance without the expense or added complexity of an all-SSD
storage system. It is server software that multiplies the speed of applications by eliminating storage bottlenecks. HGST ServerCache creates an SSD cache: a copy of the most frequently used data on an SSD so that
data access is much faster than spinning disk.
HGST FlashMAX® II is a leading PCIe Flash SSD providing high performance and high capacity in a small
half-height, half-length footprint. HGST FlashMAX II powers some of the largest enterprise applications in
the world and is known for ease of deployment and superior durability even when utilized at its maximum
capacity. Models range from 550GB to 4.8TB.
The Virtual Storage Dilemma
With the hyper dense nature of virtualized environments, current storage cannot keep up with the needs
of generating, cloning, and higher vCPU/RAM counts. All SSD arrays are expensive and difficult to maintain and configure. Growing size of environments are pushing the pendulum between speed and size back
and forth for each new project that is put on the top of the list. In the past each physical box needed more
and more hard drives to add lOPs or create a tiered SAN that could require a forklift replacement of a lot of
hardware. Time and effort by the staff and the financial requirements cause slowness to be pervasive in the
storage environment.
What is Cache and Why it Matters
Caching gives users the best of both worlds. It allows for increasing storage size and increasing the speed at
the same time. This is where the pendulum analogy breaks down. Data wants to be fast and cache allows it
to be. In the simplest terms caching is short-term recent memories. Hot data (things that you need to recall
a lot) stays in the front of your mind: Your name, phone number, address.
There are two major types of caching. One that is best for read intense workloads, write­-though caching, and
one that is best for high write workloads, write-back caching.
Read Caching (Write-through caching)
Appropriate data that is read from the disk is stored on the SSD for future high-speed read access. Reads of
the ‘hottest’ data are served from RAM, giving even higher performance. In write-through mode, the write to
disk is confirmed before the write is confirmed to the application.
Write-back Caching (persistent)
Read caching places appropriate data on the SSD for future high-speed read access and the write to disk
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Using HGST ServerCache™ with Microsoft Hyper-V
occurs at a later time. In write-back mode, the write to SSD cache is confirmed before the write is confirmed
to the application.
In write-back mode, writes in the cache that have not yet been committed to disk are recovered in the event
of an unclean shutdown. The full recovery of all acknowledged l/Os will prevent data integrity failures
following an unexpected or unclean shutdown.
The cache is fully flushed to disk when HGST ServerCache is manually shut down.
HGST ServerCache
HGST ServerCache is a plug-and-play caching software that uses a combination of Solid State Disk (SSD)
and RAM to create a transparent application acceleration layer that eliminates l/O bottlenecks. ServerCache
utilizes SSD in a unique way that delivers higher performance and lower cost than alternative SSD solutions
and reduces the complexity normally associated with adding an SSD to your system. ServerCache can be
used with any SSD and any block­based primary storage, and deploys and operates without disruption to
applications, storage or data.
Testing Setup
Hardware
Dell 720r
4 socket x 4 core CPU with hyper threading
384GB RAM
500GB Storage WD Drive
300GB OS WD Drive
2.2 FlashMAX II PCie
Software
Microsoft Server 2012 R2 Hyper-V 2012 R2
lometer 1.1
FlashMAX II driver 4.1.0.68411
FlashMAX II MAX PERFORMANCE MODE
VM running win 7 32 bit with 6GB RAM and 12 Vcpus Single 125GB Harddrive
BenchMark Specs
Read Heavy Workload: 4 KiB; 100% Read; 0% random
Write Heavy Workload: 4 KiB; 100% Write; 0% random
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Using HGST ServerCache™ with Microsoft Hyper-V
Results
The results of the benchmarking are staggering. The single SAS RAID array got upto 432 lOPs. When Cache
was enabled that number shot up over llOX to 47,891 lOPs. There was ZERO change to anything happening
on the VM itself. It was as simple as a few clicks and 110X increase in read lOs. When switching to a heavy
write workload the baseline stays at 432 lOPs, then the Cached lOps increased over 26X to 11,303 lOPs.
IOPs
60000
IOPs
50000
40000
30000
20000
10000
0
No Cache
Write Workload
Read Workload
Using the same benchmarks the MiBps also had similar leaps in throughput. Non-cached MiBps was 1.69.
When read caching was enabled that went up llOX again to 187.07 MiBps. The writes went up 27X to 46.3
MiBps.
MiBps
200
180
MiBps
160
140
120
100
80
60
40
20
0
No Cache
Write Workload
Read Workload
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Using HGST ServerCache™ with Microsoft Hyper-V
Solution
Standard Architecture
Network
Server
Application
CPU
RAM
Flash
Switch
Storage
Array
HDD
HGST ServerCache
Application
CPU
SAN
SSDs
Cached Architecture with HGST ServerCache
Network
Server
Application
CPU
RAM
Flash
Switch
Storage
Array
HDD
HGST ServerCache
Application
CPU
SSDs
SAN
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Using HGST ServerCache™ with Microsoft Hyper-V
Conclusion
When looking at the most impact you can make with the least output of money, time, and complexity, it is
clear that HGST ServerCache on the highest quality SSDs like HGST FlashMAX II will fit the bill.
© 2014 HGST, Inc., 3403 Yerba Buena Road, San Jose, CA 95135 USA. Produced in the United States. All rights reserved.
Other trademarks are the property of their respective companies.
FlashMAX is a registered trademark of HGST, Inc. and its affiliates in the United States and/or other countries. ServerCache is a trademark
of HGST, Inc. and its affiliates in the United States and/or other countries. HGST trademarks are intended and authorized for use only in
countries and jurisdictions in which HGST has obtained the rights to use, market and advertise the brand. Contact HGST for additional
information. HGST shall not be liable to third parties for unauthorized use of this document or unauthorized use of its trademarks.
References in this publication to HGST’s products, programs, or services do not imply that HGST intends to make these available in all
countries in which it operates. Product specifications provided are sample specifications and do not constitute a warranty. Information is
true as of the date of publication and is subject to change. Actual specifications for unique part numbers may vary.
Please visit the Support section of our website, www.hgst.com/support, for additional information on product specifications. Photographs
may show design models.
One GB is equal to one billion bytes and one TB equals 1,000 GB (one trillion bytes) when referring to hard drive capacity. Accessible
capacity will vary from the stated capacity due to formatting and partitioning of the hard drive, the computer’s operating system, and
other factors.
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