Is it snapshot-as-volume-chain just to LVM or can I use it to directory storage type?

[Gilberto Ferreira]

Hi...

So, that's my question:
"Is it snapshot-as-volume-chain is just to LVM or can I use it to directory storage type?"

I tried to used in directory storage type but seems that discard doesn't work properly.
I tried triggered a fstrim command with qm guest cmd VMD fstrim, but no effect at all.
After remove the snapshot-as-volume-chain option from the directory storage, fstrim works fine.
In other words, snapshot-as-volume-chain doesn't work with thin-provision, whatever is LVM-thin or directory?

Just wanna know if this is the intent design.

Thanks

[ UPDATE - 1 ]
I noticed that if I use snapshot-as-volume-chain = 1 in a directory storage type, and after took a snapshot, fstrim works fine, which made more confused for me now.

[ UPDATE - 2 ]
If I mantain at least one snapshot, discard AKA fstrim, works fine.

 

[fabian]

please note that you cannot add or remove the option, as that will break everything (it is fixed for a reason, it can only be set at storage creation time and never changed!)

 

[Gilberto Ferreira]

please note that you cannot add or remove the option, as that will break everything (it is fixed for a reason, it can only be set at storage creation time and never changed!)

I didn't saw nothing about that in the docs.(0)
Perhaps this could be include on it, to make a better understand.
Thanks.

[0] https://pve.proxmox.com/pve-docs/chapter-pvesm.html#pvesm_lvm_config

 

[fabian]

it is a fixed property, you cannot change it over the API, only if you manually edit the config file - which you should not do if you don't know what the options do/how they work.