[Users] Problems doing live migration

[Scott Dowdle]

Greetings,

----- Original Message -----
> I'm trying to do a manual live migration on a Linux
> 2.6.32-5-openvz-amd64 and
> openvz 3.0.24, but I'm getting some troubles:
> 
> .- Container's suspend seems OK.
> .- But I'm not able to dump the container:
> "Can not dump container: Invalid argument
> Error: iptables-save exited with 255
> Checkpointing failed"
> .- I can issue iptables-save command with no problem.
> .- Also, I'm not able to resume the container:
> "Can not resume container: No such file or directory"
> .- After this happens, vzctl complains about quota issues.
> 
> Here's is a session log:
> 
> ~# vzctl chkpnt 114 --suspend
> Setting up checkpoint...
>         suspend...
>         get context...
> Checkpointing completed succesfully
> ~# vzctl chkpnt 114 --dump --dumpfile /tmp/114.dump
> Setting up checkpoint...
>         join context..
>         dump...
> Can not dump container: Invalid argument
> Error: iptables-save exited with 255
> Checkpointing failed
> ~# vzctl chkpnt 114 --dump --dumpfile /tmp/114.dump
> Setting up checkpoint...
>         join context..
>         dump...
> Cannot set linkdir in kernel: Too many links
> Checkpointing failed
> ~#  vzctl chkpnt 114 --resume
> Resuming...
> Can not resume container: No such file or directory
> ~# ls -ld /var/lib/vz/*/114
> drwxr-xr-x 21 root root 4096 12 gen 12:13 /var/lib/vz/private/114
> drwxr-xr-x  2 root root 4096 10 gen  2011 /var/lib/vz/root/114
> ~# vzctl stop 114
> Stopping container ...
> Container was stopped
> vzquota : (error) Quota off syscall for id 114: Device or resource
> busy
> vzquota : (error)       Possible reasons:
> vzquota : (error)       - Container's root is not unmounted
> vzquota : (error)       - there are opened files inside container's
> root/private area
> vzquota : (error)       - your current working directory is inside a
> container
> directory
> vzquota : (error)         root/private area
> vzquota off failed [3]
> ~# vzctl start 114
> Starting container ...
> vzquota : (warning) Quota is running for id 114 already
> Container is mounted
> Adding IP address(es): 10.81.53.15
> Setting CPU units: 1000
> Container start in progress...
> ~# vzctl exec 114 reboot
> ~# vzctl stop 114
> Stopping container ...
> Container was stopped
> vzquota : (error) Quota off syscall for id 114: Device or resource
> busy
> vzquota : (error)       Possible reasons:
> vzquota : (error)       - Container's root is not unmounted
> vzquota : (error)       - there are opened files inside container's
> root/private area
> vzquota : (error)       - your current working directory is inside a
> container
> directory
> vzquota : (error)         root/private area
> vzquota off failed [3]
> 
> If I use the "vzmigrate" command, the result is similar, here's the
> last logs,
> the command issued is "vzmigrate -v -r no --keep-dst --online
> linux-01 117":
> 
> Checkpointing completed succesfully
>    Dumping container
> Setting up checkpoint...
>         join context..
>         dump...
> Can not dump container: Invalid argument
> Error: iptables-save exited with 255
> Checkpointing failed
> Error: Failed to dump container
> Resuming...
> Can not resume container: No such file or directory
> 
> Why I can not dump the container? iptables-save is there on my system
> and I can execute it, why is that command needed after all?

I'm not sure if it is talking about iptables-save in the container or on the host node.  In any case, I was having trouble migrating an Ubuntu container a while back (I don't use it anymore though) and I got that error... and if I remember correctly what I did to fix it was to make iptables-save in the container a symlink to /bin/true... and that magically made it work.  I don't know if that is going to work for you or not.

As to the why, I can't really say... I guess some people who use iptables in their containers find that useful... so that the iptables rules are saved and will be able to be restored.  I don't use iptables in my containers at all.

TYL,
-- 
Scott Dowdle
704 Church Street
Belgrade, MT 59714
(406)388-0827 [home]
(406)994-3931 [work]