Deleting data in lxc lvm thin doesn't release space

[EuroDomenii]

Tested on latest proxmox 4.4
Similar issues on docker:
- Delete data in a container devicemapper can not free used space https://github.com/docker/docker/issues/18867#issuecomment-223206599
- Device-mapper does not release free space from removed images https://github.com/docker/docker/issues/3182 ( this works on proxmox, after removing the whole lxc container the space is released) . But still the removed lxc container shows obsolete data in lvdisplay. Only after reboot are cleared.

 

[EuroDomenii]

Workaround fstrim -v /var/lib/lxc/VmID/rootfs won't help, only backup/restore

 

[fireon]

Please make an bugreport: https://bugzilla.proxmox.com/
Thank you.

 

[wbumiller]

Either run fstrim from within the container on /, or do a `pct mount $vmid` and `pct unmount $vmid` around the `fstrim /var/lib/lxc/$vmid/rootfs`
(Also make sure your LVM config has `issue_discards` enabled.)

 

[EuroDomenii]

Thank you for reply. The only thing working, from your suggestions, is fstrim inside container.
I think of running like https://forum.proxmox.com/threads/proxmox-execute-command.26030/, from outside, for my clients, on cron.

However, this is the most performant solution, according also to http://blog.neutrino.es/2013/howto-...for-your-ssd-on-linux-fstrim-lvm-and-dmcrypt/

On the other hand, I would be interesting to know why this is not working out of the box, since I have LVM config `issue_discards` enabled

 

[EuroDomenii]

fstrim inside unprivileged container fails with FITRIM ioctl failed: Operation not permitted
Tested on Ubuntu Xenial and Debian Jessie.
See bug report https://bugs.launchpad.net/ubuntu/+source/util-linux/+bug/1589289