RAID VDISK vs Windows Partitions for SQL server

[SamiSheikh]

Hi,

I am in the midst of setting up a new SQL server(mssql 2005) with two instances on Server 2k8 R2. Below are the specs of my server.

HP DL380 G7
2 x E5649(Hexacore 2.53GHZ)
16GB of RAM DDR3
4 x 600GB SAS 10k drives


So what I would like to do is have one Vdisk with Raid 5(100GB) for O/S, and the rest in Raid 10 for DATA.

I would like to have 4 logica

l drives/partitions(2 for Data for each instance and 2 for Logs for each instance)

So my question is should I carve out the data drive using windows partitions or making Vdisks from the raid controller?

I have heard by making multiple Vdisks, you are pretty much splitting I/O and killing the I/O on your server, and I am in desperate need of IOPS since it is a SQL server.

[Johan Guldmyr]

Hi, 

you assign whole disks to an array (RAID5 or RAID1, etc).

Inside the array you create logical volumes (100GB, 50GB, etc).

You cannot create a RAID5 and a RAID10 with only four disks.

But yes, if you were to have multiple arrays the IOPS would be split between those, because the disks are dedicated to an array.

How about one single RAID10 - then you can create a 100GB Logical Volume for O/S and 1100GB Logical Volume for data?

You could also in that same array create one large logical volume and then partition that as you want. 

I would look into the different strip sizes and cache ratios when you set up the array, do some performance testing too to see which is best for your workload.