SQL Server Performance Forum – Threads Archive

Drive Formats / Striping Size

I’ve not had much experience with non-default settings. The default cluster size for my windows boxes is 4K and default striping for RAID5 is 64K. I was thinking 64K clusters sizes and 128K stripping for my RAID5 array housing data files. Opinions?

What is the database growth in next 3 to 5 years?
What is the hardware specification? Satya SKJ
Microsoft SQL Server MVP
Contributing Editor & Forums Moderator
http://www.SQL-Server-Performance.Com
This posting is provided AS IS with no rights for the sake of knowledge sharing.

C: (binaries and tran logs)= 2x72GB 10K SAS
D: (SQL Data files) = 6 x 72GB 10K SAS with 256MB on RAID controller. DB is 6GB. Not worried about disk space, just performance.

Ok, how’s this. I’m toying with the idea of 64K clusters and 256K RAID5 stripe size. Or 8K cluster size and 64K RAID5 stripe size. Here’s an interesting doc: http://www.microsoft.com/whdc/device/storage/subsys_perf.mspx Unfortunately, I don’t know my workload quite as well as this doc requires. This server will be used as heavy OLTP but will ALSO be servicing all report requests related to the data. Again, the drives are 6 X 10K SAS and this is for data files. The binaries and transaction logs have been left on a mirror with default settings. Also, as a second question… My raid card has 256MB cache with 100% read allocation. I’m thinking with an OLTP system this should be at least 50% write. Any opinions on that?

Got no input for you on cluster sizes but when it comes to raid cache allocation you should not specify any write cache unless you have a battery backup for the cache as well or you will loose data in the event of a power loss. If you do have battery backup then enabling write cache will help a lot.

]]>