RAID performace

Presented with a chassis containing 24 x 1.64TB drives, would I get better performance if I created 2 RAID6 VD’s across all 24 drives or 2 RAID6 VD’s across 12 drives for each LUN???


I would do one RAID6 VD across all 24 drives. IOPS performance is will be determined by how many spinning disks are assigned in the array. Also, you’ll conserve 2 disks that would have been used in a second array.

I understand you answer, and thank you. However, I am being told by a coworker that 2 VD’s across all 24 drives performs better than 2 VDS across 12 drives each, so I don’t understand the reason for this contention…

I would build one virtual disk in the RAID controller across all 24 drives. I don’t see how it would let you do two.

A dell VRTX will allow this

Got ya. Then I would do 2 VDS across the 24 drives.

So spanning across all 24 drive increases write performance? I would instinctively think that media contention would cause a performance hit. It’s almost counter intuitive…

If there is no contention for IOPS, there will be no difference between a RAID6 made up of 12 drives or 24 drives for write operations. If there is contention, the potential benefit for having 24 drives is that the write operation could be pushed to drives that have less workload in the queue. This is all based on the RAID controller and they are not all created equal.

In my opinion, it is always good to test it if you can. I would build out the array both ways and run the same performance test against both arrays and see what happens.