I have 4 2.5" 7.2k drives lying about and I'd like to build some RAID arrays for a bit of VM storage on my KVM lab box.
There are 2x 320GB drives and 2x 500GB drives. I'm looking to create a RAID 10 array using 4x 320GB partitions. Then the remaining 180GB on the 500GB drives I'll build into a RAID 5 partition with another spare drive. I realise that performance will take a hit because half of the drives in the RAID 10 array will be used by another array and using non-matched drives is also not-optimal but this is solely for a lab/test environment.
Initially I thought I would just create 4 matching partitions, create the RAID 10 array, LVM on top and done. But I started looking into all this sector alignment business and now I don't really know where to start.
The 320GB drives report
Sector size (logical/physical): 512 bytes / 512 bytes
The 500GB drives report
Sector size (logical/physical): 512 bytes / 4096 bytes
So there are the following variables that I would need to take into account: partition start/alignment, RAID stripe size, RAID superblock position (?), LVM PV
--dataalignment, then alignment of any file systems in my LVs.
Is anyone able to run through what I'd need to do in this specific case to get optimal alignment/sector/stripe size?
Please try and ignore the fact that the mixed drives mean the whole thing isn't optimal to start with, as I said, this is a test/lab environment.