Article ID: 122460, created on Jul 23, 2014, last review on Jul 23, 2014

  • Applies to:
  • Virtuozzo 6.0
  • Virtuozzo containers for Linux 4.7
  • Virtuozzo hypervisor

Symptoms

Hardware node is running on kernel 2.6.32-042stab092.1 or 2.6.32-042stab092.2

Container is mounted and cannot be unmounted (or is stopped and can't be mounted):

[root@node ~]# vzctl umount 100500
Cannot unmount: /vz/root/100500: Device or resource busy
[root@node ~]#

Even though there are no open file handles or the container is not even shown in /proc/mounts at all.:

[root@node ~]# lsof 2>/dev/null | grep 100500
[root@node ~]#

If mount is present, it is in read-only mode:

[root@node ~]# grep 100500 /proc/mounts
/vz/template:/vz/private/100500/fs /vz/root/100500 vzfs ro,relatime,usrquota,grpquota,/vz/template:/vz/private/100500/fs 0 0

Container is still present in /proc/bc/CTID:

[root@benderbrau ~]# ls -al /proc/bc/100500
total 0
dr-x------  2 root root 0 Jul 21 11:54 .
dr-x------ 36 root root 0 Jul 21 11:54 ..
-r--------  1 root root 0 Jul 21 11:54 dcacheinfo
-r--------  1 root root 0 Jul 21 11:54 debug
-r--------  1 root root 0 Jul 21 11:54 ioacct
-r--------  1 root root 0 Jul 21 11:54 ioprio
-r--------  1 root root 0 Jul 21 11:54 iostat
...

Cause

The issue was recognized as a product bug with internal ID #PSBM-28104.

Resolution

The issue is fixed in kernel 2.6.32-042stab092.3 and newer.

To both unlock the container, and ensure issue will not reoccur install the latest available kernel and reboot the host.

Search Words

Cannot unmount

PSBM-28104

Cannot unmount ... Device or resource busy

Device or resource busy

container unable to come up after reboot

container wont start

failed to start container

read-only

a26b38f94253cdfbf1028d72cf3a498b 2897d76d56d2010f4e3a28f864d69223 e8e50b42231236b82df27684e7ec0beb d02f9caf3e11b191a38179103495106f 0dd5b9380c7d4884d77587f3eb0fa8ef 0c05f0c76fec3dd785e9feafce1099a9 c62e8726973f80975db0531f1ed5c6a2

Email subscription for changes to this article
Save as PDF