Weird bug in lxc containers

joebaires

Member
May 20, 2015
7
1
23
Hello,

Here using latest PVE 4.4-13.

Today I had to do maintenance on my main node, so I moved my containers to another node: shutdown / migrate / start (I really miss years ago when we could do live migration using openvz... can't believe we are still stuck without it in lxc).

All went ok until I found a container that for some reason had the image stored in the local disk instead of the nas mounted via nfs. So, I tried first to move it to the NAS, but, to my surprise, there is no "Move Disk" option for LXC cointainers as in full VMs.

So I tried to backup and restore, but when restoring, proxmox throw an ugly error:

Formatting '/mnt/pve/nas/images/112/vm-112-disk-1.raw', fmt=raw size=21474836480
mke2fs 1.42.12 (29-Aug-2014)
Creating filesystem with 5242880 4k blocks and 1310720 inodes
[...]
done

disk image '/mnt/pve/nas/images/112/vm-112-disk-1.raw' does not exists
TASK ERROR: volume 'nas-datos:112/vm-112-disk-1.raw' does not exist

After that, the container disappeared from the system!!

Luckily I had a backup copy of the .conf file in /etc/pve/nodes/.... so I could manually re create it.

So several things came to my attention:

- Restoring backup seems to lead to destruction of the container when there is no existing disk image (really ugly bug)

- Missing "Move Disk" option for containers (supposedly when moved from openvz to lxc one of the reasons was that it had available all the same features regarding storage, as discussed in pve docs/chapter-pct.html#pct_container_storage).

- I really don't understand why we still can't get live lxc migration two years after the initial release of proxmox 4.0. I know about CRIU project but it seems to be working for other LXC projects like docker.
 

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