ZFS file vs partition

LXD
1

I have currently got a dedicated server with 2x2TB raid setup, I am bit reluctant to try and repartition it therefore, when setting up ZFS my only option seems to be for the ZFS pool to be created as a file instead of a custom partition.

I am wondering what sort performance hit I should expect, bearing in mind the HDD is noticeably slower when installing stuff compared to SSD. Is there going to be major slowness or will be it not noticeable.

2

For HDD, the overhead may not be too noticeable given things are already quite slow.
You’ll definitely end up doing additional read/writes because of going through another filesystem.

3

Would it make sense (performance) in this situation, if i was only using LXD VMs but not containers to use the filesystem storage driver instead of a ZFS file ?

4

Yeah, I’d expect the dir backend to offer better runtime performance with the usual limitations:

  • Disk limits won’t apply to containers
  • Launching new instances will be pretty slow (no copy-on-write)
  • Snapshots are effectively useless (require a full copy of the data)
  • Migration relies on rsync and so is also slow

If you don’t create instances too often nor use snapshots, this may be fine though.