RAID10 expected performance level not met
 

hi,
after setting up a 4 drive, software RAID10 configuration on stock arch linux (2.6.30 x86_64 kernel) , benchmark using FIO with random read on 1GB test file showed no improvement on IOPS.

A single drive was able to random seek at ~150 IOPS. With 4 drives on RAID10, random seek still performs at ~150 IOPS.

However, RAID10 configuration is able to sustain 150IOPS with 2 concurrent benchmark running, while performance tanks with only 1 drive.

shouldn't raid10 increase IOPS ? any tips ?

have tried changing the disk scheduler, changing NCQ size, without noticible changes.