For an OLTP SQL workload, when making a RAID 10 with 8 drives on a PERC 6, what is the preferred span size to optimize for performance. The utility asks "physical drives per span" but I can't find any documentation that compares performance for using 2 versus 4. Thanks!

Old post I know, but does anybody have any kind of performance data for this? I was setting up a Raid 10 array and ran into this, unable to find any kind of documentation describing the differences.

"Old post I know, but does anybody have any kind of performance data for this? I was setting up a Raid 10 array and ran into this, unable to find any kind of documentation describing the differences."

Did you find a solution to this? I can't find anything either.

What a can of worms this question is lol! Im going to try and answer this one, because their are extreame variables that would have to be answered first.

Is this a perc 6/E or 6/I card? What data are you moving and whats the application in use. Are you using SATA or SAS drives. Is this a MD1000 or the new MD1220 with 6GB Ports?

What do you expect to see from your device? Direct connected storage is faster, but limited to the use of the storage plan.

What OS are you running and what version.

This is just the top of the ice berge and I strongly suggest a consultant or use Dell Professional Services and get your own team to draft and select the right solution for you. This could save you hundreds of thousands in time and equipment.

"What a can of worms this question is lol! Im going to try and answer this one, because their are extreame variables that would have to be answered first.

Is this a perc 6/E or 6/I card? What data are you moving and whats the application in use. Are you using SATA or SAS drives. Is this a MD1000 or the new MD1220 with 6GB Ports?

What do you expect to see from your device? Direct connected storage is faster, but limited to the use of the storage plan.

What OS are you running and what version.

This is just the top of the ice berge and I strongly suggest a consultant or use Dell Professional Services and get your own team to draft and select the right solution for you. This could save you hundreds of thousands in time and equipment. "

We're using 6/i and h700 cards. we're storing database files, index files, transaction log files, tempdb. OS is on other volume. (we have several RAID sets for separating out these pieces, but my understanding is that all pieces benefit from the same 64k stripe and allocation/cluster size. The span piece I'm not sure about. The drives are 15K SAS drives (300 or 600 GB). The storage device is internal disks (6Gbps). We're running WIndows Server 2008 R2 Enterprise x64. I've spoken with an engineer from Dell and he didn't know. We've already bought the servers and like them, but want to make sure we're configuring them correctly for SQL. I've been using RAID technologies for years but not till Dell Poweredge servers did I see this choice about span size. I usually pick the default (2 disks per span) which makes 4 spans for 8 disks. But if I choose 4 disks per span it makes 2.

I wonder if it will make much difference? If you create a RAID 1 with more than two drives then you have some sort of spanning occurring already within that RAID 1 set.