undeletable containers in "ERROR" state

[Martin Pitt]

Both on my amd64 laptop and on arm64 scalingstack instances I run into undeletable containers in error state over time:

$ lxc list
+---------------------+-------+------+------+------------+-----------+
| NAME | STATE | IPV4 | IPV6 | TYPE | SNAPSHOTS |
+---------------------+-------+------+------+------------+-----------+
| adt-virt-lxd-kntimp | ERROR | | | PERSISTENT | 0 |
+---------------------+-------+------+------+------------+-----------+
| adt-virt-lxd-rxwyjf | ERROR | | | PERSISTENT | 0 |
+---------------------+-------+------+------+------------+-----------+

$ lxc delete adt-virt-lxd-kntimp
error: couldn't detect filesystem for '/var/lib/lxd/containers/adt-virt-lxd-kntimp': no such file or directory

Indeed this directory does not exist any more, so it's gone from disk but still present in the database. It usually works to "sudo mkdir" this directory and "lxc delete" again.

I'll attach the corresponding /var/log/lxd/<container>/lxd.log files for these two. I don't think that they contain anything interesting, though. fork{exec,start}.log in these are empty, and lxc.conf is nothing fancy.

I keep these two failed containers around for a while (i. e. don't do the mkdir/delete trick), in case you want to investigate anything on them.

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: lxd 2.0.0-0ubuntu4
ProcVersionSignature: Ubuntu 4.4.0-22.38-generic 4.4.8
Uname: Linux 4.4.0-22-generic x86_64
ApportVersion: 2.20.1-0ubuntu2
Architecture: amd64
CurrentDesktop: i3
Date: Thu Apr 28 09:24:33 2016
EcryptfsInUse: Yes
SourcePackage: lxd
UpgradeStatus: No upgrade log present (probably fresh install)

[Stéphane Graber (stgraber)]

Not sure what's the source of the problem, but one thing we should do is allow for containers in such state to be removed.

[Stéphane Graber (stgraber)]

Tracking the workaround here: https://github.com/lxc/lxd/issues/1967

It could be that the initial cause of this was two concurrent container removals, somehow leading to both of them failing towards the end.