[SOLVED] Problems starting LXC

[Ovidiu]

Some of my LXC won't properly autostart.
What happens is that they appear to be started and yet when I pct enter ID and do a pstree all I see is this:

root@alfred:~# pstree
init───init───rc───startpar───networking───ifup───dhclient

root@alfred:~# uptime
11:41:37 up 9 min,  0 users,  load average: 0.74, 0.34, 0.14

I have about 8 LXC and 3-4 of them have this same issue. They just hang there doing nothing.
I can work around this problem by issuing a shutdown -r now inside the LXC and they will be properly back up and running fine in a few seconds.

Any thoughts on what could cause this and how to fix it?

 

[dietmar]

looks dhclient (DHCP) hangs inside the container. What kind of OS do you run inside the container?

 

[Ovidiu]

The one LXC I am sure about was hanging is running Debian 8, I only noticed as that one is the most important one ,the others are only running some "playground" scenarios and are not mission critical.

The others are a mix of Debian 8/7 and Ubuntu 12/14 and all my OS-es are always up-to-date.

I have another Debian 8 container which booted just fine.

 

[dietmar]

Maybe a problem with the DHCP server? Try to assign a fixed address for testing...

 

[Ovidiu]

All LXC containers have a fixed public IP. Shall I try and uninstall DHCP on the guests? Not sure why DHCP is even starting :-(

 

[dietmar]

Not sure why DHCP is even starting :-(

Please try to find out why dhcpd is starting then.

 

[Ovidiu]

Hm, I was never able to get IPV6 working in LXCs so I always set IPV6 to DHCP when creating a container. So I see this line in my /etc/network/interfaces - could that be the reason?

iface eth0 inet6 dhcp

 

[dietmar]

please set IPv6 to static, without adding any address.

 

[Ovidiu]

ah, I see, it never occurred to me I could do that. And that seems to have fixed the problem. Thank you very much for the hint!