Article ID: 120949, created on Apr 8, 2014, last review on Sep 3, 2015

  • Applies to:
  • Virtuozzo


Ploop container consumes significantly more disk space on the server, than the data size inside it:

[root@vz ~]# du -h /vz/private/101/root.hdd/root.hds
154G    /vz/private/101/root.hdd/root.hds

[root@vz ~]# vzctl enter 101
entered into Container 101
CT-101-bash-4.1# df -h
Filesystem         Size  Used Avail Use% Mounted on
/dev/ploop18346p1  197G   62G  133G  32% /
none               1.0G  4.0K  1.0G   1% /dev


Depending on the data structure inside a container, a scheduled daily job that compacts ploop images automatically, /etc/cron.d/pcompact, might not be effective. One of the possible reasons of such behavior is high fragmentation level inside a container.


Optimizations of pcompact are planned in future Virtuozzo updates in scope of request with internal ID #PSBM-30164.

For now, there are few methods to compact a container manually.

  • Truncate unused blocks with the help of prl_disk_tool utility:

    [root@vz ~]# prl_disk_tool compact --hdd /vz/private/101/root.hdd/
  • Downsize stopped container and upsize it back to the original value:

    [root@vz ~]# vzctl stop 101
    [root@vz ~]# prl_disk_tool resize --hdd /vz/private/101/root.hdd --size 75000M
    [root@vz ~]# prl_disk_tool resize --hdd /vz/private/101/root.hdd --size 199000M

Search Words

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