backup needs much more space than the LXC itself

[fruchtzwerg]

I have a lxc container in pve. The webgui shows me an amount of storage of 12.69 GB.


The backup in PBS needs more than 20GB.

I cannot afford this amount of storage and would like to shrink the storage of the backup.
But how?

 

[Impact]

Can you check if it gets smaller if you call pct fstrim CTIDHERE first? Maybe some files change very often or there's some sparse files or something.

 

[fruchtzwerg]

I tried pct fstrim CTIDHERE

with the output:

fstrim: /var/lib/lxc/306/rootfs/: the discard operation is not supported

Maybe I should mention that I use zfs.
The lxc is a yunohost server. Nothing special.

 

[fiona]

Hi,
it could be that ZFS just reports a lower value because of compression (you can check with zfs get all path/to/your/subvol | grep compress) or there could also be sparse files. But please note that the PBS storage usage is not at all the sum of those sizes, it also has compression and also deduplication: https://pbs.proxmox.com/docs/introduction.html#main-features See the Deduplication Factor in your Datastore summary

 

[fruchtzwerg]

Hi,
it could be that ZFS just reports a lower value because of compression (you can check with zfs get all path/to/your/subvol | grep compress) or there could also be sparse files. But please note that the PBS storage usage is not at all the sum of those sizes, it also has compression and also deduplication: https://pbs.proxmox.com/docs/introduction.html#main-features See the Deduplication Factor in your Datastore summary

I'm confused. Does that mean that the lxc has indeed an amount of round about 22GB?
My purpose was to shrink its size.

 

[fruchtzwerg]

If there are sparse files how could I deal with them?