[lxc-devel] lxc-checkpoint error

[Ruslan Kuprieiev]

Hi Tycho,

On 03/24/2015 04:21 PM, Tycho Andersen wrote:
> Hi Ruslan,
>
> On Tue, Mar 24, 2015 at 10:14:02AM +0200, Ruslan Kuprieiev wrote:
>> Hi Axel,
>>
>> On 03/24/2015 01:17 AM, Axel Schöner wrote:
>>> Am Montag, 23. März 2015, 15:42:47 schrieb Ruslan Kuprieiev:
>>>> Hi!
>>>>
>>>> I'm trying to use lxc-checkpoint to dump/restore simple lxc container.
>>>>
>>>> I added:
>>>> |# hax for criu
>>>>
>>>> lxc.console = none
>>>> lxc.tty = 0
>>>> lxc.cgroup.devices.deny = c 5:1 rwm|
>>>>
>>>> to container config, but when I'm trying to run
>>>>
>>>> |lxc-checkpoint -n $name -D $checkpoint_dir -s -v|
>>>>
>>>> I get:
>>>> Error (mount.c:624): 113: ./sys/fs/cgroup/perf_event doesn't have a
>>>> proper root mount
>>> The problem is, that "/sys/fs/cgroup/perf_event" is in your case a bindmount
>> >from outside (host).
>>> CRIU can dump extern ressources which are bind mounted, you can find details
>>> on: http://www.criu.org/External_bind_mounts.
>>> lxc-checkpoint does not care about /sys/fs/cgroup/perf_event.
>> Thanks for a hint.
>>
>> But shouldn't lxc-checkpoint just work? I mean, it should dump/restore lxc
>> container, so it probably should handle perf_event too.
> Unfortunately, the recent autodev patches have broken lxc-checkpoint.
> I'm working on some patches to criu to properly resolve mount points as
> autodev does them, but I haven't gotten anything working yet.
>
> Another problem is that systemd mounts propagate differently (SLAVE vs
> PRIVATE), and that confuses criu as well. I'm now back focused more on
> migration/criu vs LXD proper, so fixes should be rolling in in the
> coming weeks, hopefully.


Oh! So everything should be working on a bit older ubuntu, right?
I saw your doom migration demo and your instructions in your blog,
so looks like it clearly worked well for you =).
I might just try using a previous one, as I'm currently using the
most recent ubuntu server for my experiments.

> That said, can you show /proc/<pid>/mountinfo for init? It looks like
> your cgroups may be mounted in yet another configuration that we're
> not prepared to handle that I haven't seen before.

Sure. Do you mean init like the init process of the host, right? If so, 
here it is:

16 21 0:15 / /sys rw,nosuid,nodev,noexec,relatime - sysfs sysfs rw
17 21 0:3 / /proc rw,nosuid,nodev,noexec,relatime - proc proc rw
18 21 0:5 / /dev rw,relatime - devtmpfs udev 
rw,size=239064k,nr_inodes=59766,mode=755
19 18 0:12 / /dev/pts rw,nosuid,noexec,relatime - devpts devpts 
rw,gid=5,mode=620,ptmxmode=000
20 21 0:16 / /run rw,nosuid,noexec,relatime - tmpfs tmpfs 
rw,size=50132k,mode=755
21 0 252:0 / / rw,relatime - ext4 /dev/mapper/ubuntu--vg-root 
rw,errors=remount-ro,data=ordered
22 16 0:17 / /sys/fs/cgroup rw,relatime - tmpfs none rw,size=4k,mode=755
23 16 0:18 / /sys/fs/fuse/connections rw,relatime - fusectl none rw
24 16 0:6 / /sys/kernel/debug rw,relatime - debugfs none rw
25 16 0:10 / /sys/kernel/security rw,relatime - securityfs none rw
26 20 0:19 / /run/lock rw,nosuid,nodev,noexec,relatime - tmpfs none 
rw,size=5120k
27 20 0:20 / /run/shm rw,nosuid,nodev,relatime - tmpfs none rw
28 20 0:21 / /run/user rw,nosuid,nodev,noexec,relatime - tmpfs none 
rw,size=102400k,mode=755
29 16 0:22 / /sys/fs/pstore rw,relatime - pstore none rw
57 21 0:35 / /var/lib/lxcfs rw,nosuid,nodev,relatime - fuse.lxcfs lxcfs 
rw,user_id=0,group_id=0,allow_other
58 21 8:1 / /boot rw,relatime - ext2 /dev/sda1 rw
59 22 0:34 / /sys/fs/cgroup/systemd rw,nosuid,nodev,noexec,relatime - 
cgroup systemd 
rw,release_agent=/run/cgmanager/agents/cgm-release-agent.systemd,name=systemd

Thanks,
Ruslan

> Thanks,
>
> Tycho
>
>>>
>>>
>>>> Could you give me a hint on what is going on?
>>>> I also saw that other people do experience the same problem:
>>>> http://tycho.ws/blog/2014/09/container-migration.html
>>>>
>>>> Thanks,
>>>> Ruslan
>> Thanks,
>> Ruslan
>> _______________________________________________
>> lxc-devel mailing list
>> lxc-devel at lists.linuxcontainers.org
>> http://lists.linuxcontainers.org/listinfo/lxc-devel
> _______________________________________________
> lxc-devel mailing list
> lxc-devel at lists.linuxcontainers.org
> http://lists.linuxcontainers.org/listinfo/lxc-devel