Article ID: 120308, created on Feb 25, 2014, last review on Jun 17, 2016

  • Applies to:
  • Virtuozzo 6.0


The container cannot be stopped or restarted, its ploop device is locked by a snapshot deleting operation:

  [root@pcs ~]# ps aux | grep snapshot
  root      851457  0.0  0.0  27424  1836 ?        D    Feb13   0:00 /usr/sbin/vzctl --skiplock  snapshot-delete 116198 --uuid {87c1be99-f8e4-4118-a855-2d2062b377d8}

or by a stop signal:

[root@pcs ~]# ps auxfwww | grep ' D '
root      764885  0.0  0.0  33744  2008 ?        D    Mar04   0:01  \_ vzctl stop 1174590

The stack of the hung process is similar to the following:

  [root@pcs ~]# cat /proc/851457/stack
  [<ffffffffa03e275a>] ploop_map_destroy+0x13a/0x170 [ploop]
  [<ffffffffa03de6ee>] ploop_merge+0x44e/0x4c0 [ploop]
  [<ffffffffa03df648>] ploop_ioctl+0x3a8/0x1750 [ploop]
  [<ffffffff8126e237>] __blkdev_driver_ioctl+0x27/0x80
  [<ffffffff8126e93d>] blkdev_ioctl+0x1ed/0x6e0
  [<ffffffff811e301c>] block_ioctl+0x3c/0x40
  [<ffffffff811ba052>] vfs_ioctl+0x22/0xa0
  [<ffffffff811ba1f4>] do_vfs_ioctl+0x84/0x5b0
  [<ffffffff811ba76f>] sys_ioctl+0x4f/0x80
  [<ffffffff8100b102>] system_call_fastpath+0x16/0x1b
  [<ffffffffffffffff>] 0xffffffffffffffff


The issue is recognized as a product bug with internal ID PSBM-24436/PSBM-23905. Fixed in 2.6.32-042stab084.20 kernel.


Install the updates to avoid the issue in the future.

The only possible way to release the container, once it got locked, is to reboot the hardware node.

Search Words

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