Multiple files in FileGroup on RAID

We are putting out DBs on a RAID array and have the data and indexes in
their own file groups. My question is where can I find information about any
performance gain in I/O based on the number of files I have in the
FileGroup.
The array is made up of 14 drives with 1 hot spare (RAID 5). How many
files?
Thx"cw3" <cw@.3mc.com> wrote in message
news:%23yenkyNnDHA.3688@.TK2MSFTNGP11.phx.gbl...
> We are putting out DBs on a RAID array and have the data and indexes in
> their own file groups. My question is where can I find information about
any
> performance gain in I/O based on the number of files I have in the
> FileGroup.
> The array is made up of 14 drives with 1 hot spare (RAID 5). How many
> files?
>
Spreading out the data to multiple files in a filegroup on top of a single
RAID 5 array is redundant. Each file will be spread out over all 14 drives
by the RAID striping to begin with. It's useless do do it again with
multiple files per filegroup.
In your setup you needn't even bother putting data and indexes into seperate
filegroups.
If you had your disks RAIDed into 7 seperate 2 drive RAID 1 mirrors, then
you might spread a filegroup over multiple volumes for performance and
capacity.
But a better configuration might be to bundle the mirrored sets into 4-drive
stripe and mirror sets.
David|||While there can be performance gains with having multiple files per file
group there is no chart etc. that exists to show what your after. The gains
are going to be greatest with lots of drive arrays and lots of processors
when you have multiple files. Chances are you will not max out the
capabilities of the way you have it now with that hardware setup.
--
Andrew J. Kelly
SQL Server MVP
"cw3" <cw@.3mc.com> wrote in message
news:%23yenkyNnDHA.3688@.TK2MSFTNGP11.phx.gbl...
> We are putting out DBs on a RAID array and have the data and indexes in
> their own file groups. My question is where can I find information about
any
> performance gain in I/O based on the number of files I have in the
> FileGroup.
> The array is made up of 14 drives with 1 hot spare (RAID 5). How many
> files?
> Thx
>