HP LeftHand SAN Solutions Support Document - Application Notes - Virtualization SAN - Performance

and Exchange benchmarks illustrate the expected performance in those

application environments. Simple file copies show throughput in megabytes

per second (MB/sec) and IOmeter simulates IOPS (inputs/outputs per second)

and throughput.

Microsoft SQLIOStress - The SQLIOStress utility was written and is

maintained by the Microsoft SQL Server Escalation staff. Designed to help

detect possible I/O path problems that would lead to Microsoft SQL Server

data corruption or loss, it emulates different SQL server database versions

and types and reports on some basic benchmarks. At a minimum it runs 5

iterations. Only the third and fourth iterations should be used for comparing

performance according to the SQLIOStress tool documentation. For this

document the 4th iteration will be used. The SQLIOStress test runs from only

a single host and typically becomes CPU bound. The tool is not capable of

scaling at the same rate as the SAN. Some scaling is achieved on a single host

due to the lower latency in the SAN.

Best Practice - Keep the data files and logs for SQL databases on

separate volumes.

Microsoft Exchange Jetstress – The Jetstress tool that allows

administrators to verify the performance and stability of the disk subsystem

before putting their Exchange server into a production environment. It

reports back to the administrator with an html document that contains

results and a PASS or FAIL for the overall test. A PASS or FAIL is strictly

based on specific test results not exceeding Microsoft specified limits. Disk

Latency is the primary metric used by Jetstress for PASS / FAIL criteria. The

values to pass are the log avg. disk sec/write, database page fault stalls, and

database avg. disk sec/read. Log average latency should be below 10ms,

database page fault stalls should always be 0, and database average read

latency should be less than 20ms. LeftHand Networks uses an automated

command line version of Jetstress that will increase threads until the test no

longer passes and records the IOPS of the last passing run. The highest IOPS

achieved while still passing is the value reported in this paper.

Best Practice – Keep the email database files and log files on

separate volumes.

File Copy Using Robust File Copy - The file copy test is a straight-forward

Windows file copy. Using robocopy.exe a file copy of one hundred 100MB files

is done from direct attached storage (DAS) in the server to a volume on the

SAN. For this test a simple measurement of megabytes per second is taken.

Robocopy (Robust File Copy) is included in the Windows resource kit. While

individual file copy speeds are limited by the nature of low queue depth disk