I have a disk shelve with 30x 6TB disks and a HW RAID Controller. I plan to set those up as RAID 10, giving me 90TB of usable space for write-heavy workloads.
The minimum number of disks for RAID 10 is 4 and while each additional pair of disks would still increase IOPS the actual gain decreases. I found that an (unofficial) optimum would be around 6 to 8 disks per RAID 10 volume (giving about 225-400 IOPS with 7.2k SATA drives).
Most example on the web consider 4-disk setups. I found (only) one resource implicitly suggesting to build multiple small RAID10 volumes and concatenate (not: stripe) those using LVM.
What would be the better (i.e. technically sound) setup:
- 5x 6-disk RAID10 concatenated by LVM
- 1x 30-disk RAID10 (if supported by the controller)
- any alternative solution I am missing