[SOLVED] LXC Snapshot Details?

[verulian]

From my wiki reading (perhaps missed details and thus my confusion) some things aren't entirely clear so I wanted to hopefully get some more details here.

I have an LXC guest on Proxmox 7.2 with ZFS compression enabled:
zfs set compress=zstd rpool/data/subvol-211-disk-0

The volume is currently about 60GB and I need to do some upgrades that could be relatively serious. I'd like to create a Snapshot first (Datacenter → PVE → LXC system → Snapshots → Take Snapshot), but I'm wondering how snapshots are generated and handled in Proxmox 7.2.

If I do this will this snapshot functionality create ZFS differential snapshots so as to minimize the amount of space they take? My goal is to run the snapshot, then if things work out over the next couple weeks, eventually remove the snapshot so as to reduce any additional storage that might be in use over time from keeping it hanging around.

I kinda just want to understand the situation fully about snapshot creation, deletion and management for LXC guests before I go hog wild here...

 

[fabian]

yes, snapshots are always storage snapshots, what exactly that means depends on the underlying storage for VMs, you can optionally also dump the guest state including memory into a storage volume (similar to "hibernation"). this is not to be confused with the 'snapshot' mode when making backups - here, only containers will actually utilize storage snapshots, a VM will use a qemu-internal CoW/snapshotting mechanism.

 

[verulian]

Thank you @fabian. So from what you're saying I interpret the following to be the case: when I use the aforementioned snapshotting mechanism on LXC guests it will use ZFS snapshotting when stored on an ZFS volume. Right?

 

[Dunuin]

Thank you @fabian. So from what you're saying I interpret the following to be the case: when I use the aforementioned snapshotting mechanism on LXC guests it will use ZFS snapshotting when stored on an ZFS volume. Right?

jup