[CRIU] dumping LXC 1.0 container failed - unable to open irmap-cache: No such file or directory

[Pavel Emelyanov]

On 03/05/2014 07:26 PM, Andrew Vagin wrote:
> On Wed, Mar 05, 2014 at 05:10:44PM +0200, David Shwatrz wrote:
>> Hi,
>> Thanks, Andrew, for your quick response.
>> The container is fedora 20 (as well as the host).
> 
> Sorry, but systemd inside CT is not supported yet for a few
> reasons. We are going to support systemd in a near future.

Andrew, so what exact problem is David currently facing?
The cgroupfs mounted inside CT?

> Thanks.
> 
>>
>> It is impossible to unmount systemd cgroups in this container:
>>
>> For example,
>> umount /sys/fs/cgroup/systemd
>> umount: /sys/fs/cgroup/systemd: target is busy
>>         (In some cases useful info about processes that
>>          use the device is found by lsof(8) or fuser(1).)
>>
>> I will test with an Ubuntu container.
>>
>> Following here is the requested output of cat /proc/4983/mountinfo
>> gives:
>> 255 195 8:5 /var/lib/lxc/fedora/rootfs / rw,relatime master:1 - ext4
>> /dev/sda5 rw,data=ordered
>> 256 255 0:5 /.lxc/fedora.ef29892550ef9cbf /dev rw,nosuid master:2 -
>> devtmpfs devtmpfs rw,size=1514576k,nr_inodes=378644,mode=755
>> 196 256 0:39 / /dev/pts rw,relatime - devpts devpts
>> rw,gid=5,mode=620,ptmxmode=666
>> 193 255 0:37 / /proc rw,nosuid,nodev,noexec,relatime - proc proc rw
>> 194 255 0:40 / /sys rw,nosuid,nodev,noexec,relatime - sysfs sysfs rw
>> 197 256 0:41 / /dev/shm rw,nosuid,nodev - tmpfs tmpfs rw
>> 198 255 0:42 / /run rw,nosuid,nodev - tmpfs tmpfs rw,mode=755
>> 199 194 0:43 / /sys/fs/cgroup rw,nosuid,nodev,noexec - tmpfs tmpfs rw,mode=755
>> 200 199 0:20 / /sys/fs/cgroup/systemd rw,nosuid,nodev,noexec,relatime
>> - cgroup cgroup
>> rw,xattr,release_agent=/usr/lib/systemd/systemd-cgroups-agent,name=systemd
>> 201 199 0:22 / /sys/fs/cgroup/cpuset rw,nosuid,nodev,noexec,relatime -
>> cgroup cgroup rw,cpuset,clone_children
>> 202 199 0:23 / /sys/fs/cgroup/cpu,cpuacct
>> rw,nosuid,nodev,noexec,relatime - cgroup cgroup rw,cpuacct,cpu
>> 203 199 0:24 / /sys/fs/cgroup/memory rw,nosuid,nodev,noexec,relatime -
>> cgroup cgroup rw,memory
>> 204 199 0:25 / /sys/fs/cgroup/devices rw,nosuid,nodev,noexec,relatime
>> - cgroup cgroup rw,devices
>> 205 199 0:26 / /sys/fs/cgroup/freezer rw,nosuid,nodev,noexec,relatime
>> - cgroup cgroup rw,freezer
>> 206 199 0:27 / /sys/fs/cgroup/net_cls rw,nosuid,nodev,noexec,relatime
>> - cgroup cgroup rw,net_cls
>> 207 199 0:28 / /sys/fs/cgroup/blkio rw,nosuid,nodev,noexec,relatime -
>> cgroup cgroup rw,blkio
>> 208 199 0:29 / /sys/fs/cgroup/perf_event
>> rw,nosuid,nodev,noexec,relatime - cgroup cgroup rw,perf_event
>> 209 199 0:30 / /sys/fs/cgroup/hugetlb rw,nosuid,nodev,noexec,relatime
>> - cgroup cgroup rw,hugetlb
>> 210 194 0:33 / /sys/kernel/config rw,relatime - configfs configfs rw
>> 211 194 0:6 / /sys/kernel/debug rw,relatime - debugfs debugfs rw
>> 212 255 0:44 / /tmp rw - tmpfs tmpfs rw
>> 213 256 0:36 / /dev/mqueue rw,relatime - mqueue mqueue rw
>> 214 256 0:45 / /dev/hugepages rw,relatime - hugetlbfs hugetlbfs rw
>>
>>
>> DavidS
>>
>> On Wed, Mar 5, 2014 at 4:45 PM, Andrew Vagin <avagin at parallels.com> wrote:
>>> On Wed, Mar 05, 2014 at 03:54:33PM +0200, David Shwatrz wrote:
>>>> Christopher,
>>>> Yes, you are absolutely right. In tests which I had done with a simple
>>>> process (not  in a containers environment), everything with c/r worked
>>>> fine, but this same message still appeared.
>>>>
>>>>> Error (mount.c:430): Mount 327 (master_id: 2 shared_id: 0) has >unreachable sharing
>>>>
>>>> Any ideas how can we tell to which mount/mount point is this message related ?
>>>
>>> Could you show content of /proc/4983/mountinfo?
>>>
>>> What distribution do you use in CT?
>>>
>>> criu doesn't support cgroup, hugetlbfs, fusectl, configfs, mqueue,
>>> debugfs file systems in containers, so you should umount them from CT.
>>>
>>> http://criu.org/LXC
>>>
>>>>
>>>> Regards.
>>>> DavidS
>>>>
>>>>
>>>>
>>>> On Wed, Mar 5, 2014 at 2:55 PM, Christopher Covington
>>>> <cov at codeaurora.org> wrote:
>>>>> On 03/05/2014 05:32 AM, David Shwatrz wrote:
>>>>>> Hello,
>>>>>> I am trying to checkpoint an LXC 1.0 container and it fails.
>>>>>> I am trying it with crtools 1.2.
>>>>>>
>>>>>> The command I use is:
>>>>>> criu dump -t 4983 -v4 -D images --shell-job --ext-unix-sk -o dump.log
>>>>>> --tcp-established --file-locks
>>>>>> and the log file shows this as a first error:
>>>>>> unable to open irmap-cache: No such file or directory
>>>>>> the full log fine is in:
>>>>>> http://pastebin.com/e3MKxmBg
>>>>>
>>>>> The irmap stuff is spurious. This looks like your real error:
>>>>>
>>>>> Error (mount.c:430): Mount 327 (master_id: 2 shared_id: 0) has unreachable sharing
>>>>>
>>>>> Regards,
>>>>> Christopher
>>>>>
>>>>> --
>>>>> Employee of Qualcomm Innovation Center, Inc.
>>>>> Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
>>>>> hosted by the Linux Foundation.
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