Performance Benefit from Partitioning RAID?

invulnarable27

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Jan 26, 2011
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Hello,

I have a server with 6 HDD's setup in a RAID 10 array. I was wondering if partitioning this chunk (2.8TB in Windows Explorer) will bring forth any performance benefits. I read that RAID 10 naturally utilizes all disks so is this necessary?

Or will partitioning solely make management task easier? (defrag, antivirus scan, etc.)

I am planning to run SQL Server and am wondering if I separate the OS, data, log, and tempdb will it improve throughput.

Thanks
 
Solution
Partitioning can help improve access times and transfer rates IF you partition the RAID volume and use ONLY the first partition. This is because you're basically using only the outermost tracks on all of the drives and:

(a) those tracks have the most data and therefore the fastest transfer rate, and
(b) by only using some of the tracks you're reducing the seek time

If you create multiple partitions and place frequently used files into different partitions then chances are you'll end up slowing things down by forcing the access arms to constantly move back and forth between them.
Partitioning can help improve access times and transfer rates IF you partition the RAID volume and use ONLY the first partition. This is because you're basically using only the outermost tracks on all of the drives and:

(a) those tracks have the most data and therefore the fastest transfer rate, and
(b) by only using some of the tracks you're reducing the seek time

If you create multiple partitions and place frequently used files into different partitions then chances are you'll end up slowing things down by forcing the access arms to constantly move back and forth between them.
 
Solution

invulnarable27

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Jan 26, 2011
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thanks for your reply sminlal. So do you think I'm better off just leaving the raid array as 1 big partition? I want the SQL writes/reads to be as fast as possible. Should I at least separate the OS from SQL (data)?
 
There are good arguments for putting the OS into its own partition for management reasons - it makes it simpler to do an image backup and restore of the OS itself and reduces the risk of OS upgrades causing issues for your data. In fact similar arguments can be made to recommend putting the OS onto it's own separate RAID-1 volume separate from the RAID 1+0 volume that holds your data.