[Lxc-users] pivot root failures when "/" is mounted as "shared"

[Peter Simons]

Hi Michael,

 >>   # xterm
 >>   xterm: Error 32, errno 2: No such file or directory
 >>   Reason: get_pty: not enough ptys
 >
 > This was in the host? That seems very strange. Then too, it might not
 > be necessary to do the "recursive private" (make-rprivate) either,
 > just make-private on the partition which contains the containers.

these errors occur on the host system regardless of whether '/' is
remounted as 'private' or 'rprivate'. Both choices lead to the same
result: after running the container, the following mount points have
disappeared from the host:

  | none on /sys/kernel/security type securityfs (rw,relatime)
  | tmpfs on /dev/shm type tmpfs (rw,nosuid,nodev,relatime)
  | none on /proc/bus/usb type usbfs (rw,relatime)
  | devpts on /dev/pts type devpts (rw,nosuid,noexec,relatime,gid=3,mode=620,ptmxmode=000)
  | cgroup on /sys/fs/cgroup/systemd type cgroup (rw,nosuid,nodev,noexec,relatime,release_agent=/nix/store/i1qpxmqwwn247y59lf2cpra5iw1rgvrh-systemd-195/lib/systemd/systemd-cgroups-agent,name=systemd)
  | cgroup on /sys/fs/cgroup/cpuset type cgroup (rw,nosuid,nodev,noexec,relatime,cpuset)
  | cgroup on /sys/fs/cgroup/cpu,cpuacct type cgroup (rw,nosuid,nodev,noexec,relatime,cpuacct,cpu)
  | cgroup on /sys/fs/cgroup/memory type cgroup (rw,nosuid,nodev,noexec,relatime,memory)
  | cgroup on /sys/fs/cgroup/devices type cgroup (rw,nosuid,nodev,noexec,relatime,devices)
  | cgroup on /sys/fs/cgroup/freezer type cgroup (rw,nosuid,nodev,noexec,relatime,freezer)
  | cgroup on /sys/fs/cgroup/blkio type cgroup (rw,nosuid,nodev,noexec,relatime,blkio)
  | hugetlbfs on /dev/hugepages type hugetlbfs (rw,relatime)
  | mqueue on /dev/mqueue type mqueue (rw,relatime)
  | debugfs on /sys/kernel/debug type debugfs (rw,relatime)

As it is right now, lxc seems to be pretty much unusable with host
systems that run recent versions of systemd. :-(

Take care,
Peter