SAN Stripe size – 64k or 128k | SQL Server Performance Forums

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SAN Stripe size – 64k or 128k

Hi, My company is in the planning stage of moveing our SQL environment onto a an EMC CX700 SAN. EMC have suggested for the SQL drives (data & logs) that we use a stripe size of 128k. I do not know how in tune with SQL they are… Historically on SCSI devices we’ve always used 64k – 8k pages, 8 pages to an extent blah blah. As 128 is a mulitple of 64 I can understand 128 being suitable. Does anyone have any opinions or know of any testing for this? Any advice greatly appreciated! Thanks
Simon
128K is a reasonable stripe size at the RAID controller level,
i would suggest that you get the vendor to guarantee a certain random and sequential read/write IO rates the storage array you purchase will achieve. i have seen too many expensive SAN solutions that achieve worse performance than a single notebook hard drive.
use IOMeter (developed by intel, now on sourceforge.net) to test the disk array.
i will probably provide SQL scripts for for generating random and sequential IO patterns in the near future
Microsoft also has a tool you may want to check out SQLIO and SQLIOStress http://www.microsoft.com/downloads/…5B-84E4-4F24-8D65-CB53442D9E19&displaylang=en http://support.microsoft.com/defaul…port/kb/articles/q231/6/19.asp&NoWebContent=1 as for EMC – trust but check, run the tests for youself to see if what they say have merit.
It would seem EMC do actually recommend 64k for SQL Server. However, I still intend to test this once it is up and running using Simas’ tool. Thanks for the help.
In the CX700, a stripe size of 128 actually indicates 128 clusters which amounts to 64K. So you are both talking about the same thing in different languages. Read the RAID section (Section 2) of the CX700 Storage systems configuration and planning guide available on the Dell web site.
A little of topic… I’m not sure the CX700 has the same issue as the CX300 but if so make sure you correct the disk offset when you create your LUNS. We use 128 stripe size with our CX300’s and CX700’s.
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