I am new to proxmox and I just setup a second node, it has an ssd that is running the pve and then I have 3 other drives a 500GB, 1.5TB, and 2TB. My idea was to combine the 500 and 1.5 in some way (using vdevs?) and the have it mirror the 2tb and use it for backups or something else not sure yet. Using zfs I couldn't put the drives in a stripe and the LVMs don't allow you to combine drives so I'm not sure if this is possible.
Combining different sized drives
- Thread starter px_user
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The error messages are a good indicator that it is not something that you should normally do, because it starts to get unpredicable (in a very limited way).
Merging 3 drives of different sizes is always difficult, but it works to some extend - if you really want to. There are numerous ways, one could be to partition the drives and create a mirrored vdev (if that is the intention of your combining) out of a 1,5 TB partition of your 2 TB drive and the 1,5 TB drive. I'd recommend to leave the rest of the 2 TB unused in order to get predicable IOPS from the big drive and not combine the remaining 500G with the 500G drive. You will - depending on the workload - have half of the performance of a single drive for all pools, otherwise you will get the double that performance, so the performance of a single drive.
The other would be what you suggested, but this involves having two different raid technologies involved:
- mdadm software raid to combine the 1,5 TB and 0,5 TB drive to one 2 TB volume
- ZFS software raid to combine the 2 TB drive and the mdadm 2 TB virtual drive