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

[Andrew Vagin]

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.

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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