[lxc-users] Ephemeral containers on Arch Linux

[Serge Hallyn]

Quoting Daniel Ellison (daniel at syrinx.net):
> Hi all,
> 
> This is my first post to the lxc-users list. I did search the
> archives for an answer to my question but didn't find any reference
> to this issue.
> 
> I'm running Arch Linux with kernel 3.18.4. I've modprobed the
> "overlay" module:
> 
> $ lsmod | grep overlay
> overlay                36114  0
> 
> This setup works perfectly for regular containers; I have several
> running with various OS installations. But when I try to create an
> ephemeral container:
> 
> sudo lxc-start-ephemeral -o keystone-base -n keystone
> 
> I get: "The container 'keystone' failed to start". No other error
> messages. Specifying "-U overlayfs" doesn't help either. How do I
> find out what's going wrong? There's no
> /var/log/lxc/keystone-base.log. I purposely omitted the -d flag so I
> could see any startup messages but it gives only the error message
> above. Starting the keystone-base container normally works fine:
> 
> NAME           STATE    IPV4         IPV6  AUTOSTART
> ----------------------------------------------------
> keystone-base  RUNNING  10.0.62.105  -     NO
> 
> Any ideas? The only discrepancy I can see is that the module on Arch
> is called "overlay" but lxc-start-ephemeral only accepts "overlayfs"
> or "aufs" as union-type. Maybe few people run LXC on Arch so this
> hasn't come up before now?

Which version are you running?  The fix for this was pushed pretty
recently so you may want to just build your own package, or patch
/usr/bin/lxc-start-ephemeral yourself with the last few commits
from git HEAD to src/lxc/lxc-start-ephemeral.in.