ZFS thin provision not enabled by default (Proxmox 7.1)

[kariboo92]

Hi
when creating a new zfs volume, compress is on by default, but storage is configured with thin provision disabled.

Is there a reason why thin provision is not enabled ?
Does compression on makes thin provision useless ?

Should we create the zfs volume manually instead of using proxmox UI ?

Thanks

 

[leesteken]

ZFS is not inherently thin or not. When creating a ZFS pool, you don't have to choose between the two upon creation as it can be turned on and off whenever you like in the Storage settings (after which it will be used for newly created virtual disks).
I assume that it is not enabled by default when you select Add Storage when creating a new ZFS pool just because there is no such option in that screen (because you do not have to choose at the time of creation of the pool). This might be an oversight or intentional, I cannot say. Some other Storage options (blocksize, nodes, content) can also only be set afterwards,

I may have misunderstood your questions, but I think you can do all this via the GUI and you don't need to do it manually or that it's related to compression.

 

[kariboo92]

Thanks,
in fact the real question is:
is there an advantage enabling thin provision ( manually or within promox UI ) when ZFS compress is on ?

 

[Dunuin]

Thanks,
in fact the real question is:
is there an advantage enabling thin provision ( manually or within promox UI ) when ZFS compress is on ?

It doesn't matter if compression is enabled or not. Those wont effect each other. If you want to make use of thin-provisioning then enable it, if not then not.
ZFS is a Copy-on-Write filesystem so you want to use discard/TRIM anyway. The difference when not checking the "thin" checkbox in GUI for your ZFS pool is that then the "refreservation" ZFS option will be set for the zvols.

 

[surfing713]

Thanks,
in fact the real question is:
is there an advantage enabling thin provision ( manually or within promox UI ) when ZFS compress is on ?

When Thin Provisioning is disabled, Proxmox sets a reservation on the zvol to reserve that space from the pool, ensuring that the pool does not allow oversubscription of disk space.
So you need to enable both Thin Provisioning to allow disk space oversubscription and Compression to save disk space.