[Users] vzctl compact fails to compact container, what can i do

[Andrew Vagin]

On Mon, Dec 23, 2013 at 04:28:14PM +0700, Rene C. wrote:
> Indeed, that seems to have been at least part of the problem, thanks much.
> 
> Still, after having removed all snapshots and rerun vzctl compress, I
> still ended up with a pigz compressed backup of 40G for a container
> with 2G used disk space (shown by df -h within the container).  Any
> idea how that can happen?

Yes, I have. The size of ploop clusters is 1MB. It's much bigger than
a file system block size (4KB). The file system can allocate 1 block
(4K), but one cluster (1Mb) on ploop will be allocated.

If a file system spreads blocks far from each other, it can freeze much
more space in ploop image.

We know this problem and going to fix it in a near future.

> 
> On Sat, Dec 21, 2013 at 11:13 PM, Andrew Vagin <avagin at parallels.com> wrote:
> > On Sat, Dec 21, 2013 at 09:08:43PM +0700, Rene C. wrote:
> >> We have a container that needs moving to another hardware node, but a
> >> vzpbackup of it is 250G.
> >>
> >> Within the container only 1.9G is used:
> >>
> >> /dev/ploop33244p1  393G  1.9G  371G   1% /
> >>
> >> Tried running a vzctl compact but it just shows a few lines and stops
> >> without having done anything:
> >>
> >> # vzctl compact 1709
> >> Trying to find free extents bigger than 0 bytes
> >> Waiting
> >> Call FITRIM, for minlen=33554432
> >> Call FITRIM, for minlen=16777216
> >> Call FITRIM, for minlen=8388608
> >> Call FITRIM, for minlen=4194304
> >> Call FITRIM, for minlen=2097152
> >> Call FITRIM, for minlen=1048576
> >> 0 clusters have been relocated
> >>
> >> /vza1/private/1709/root.hdd has following files:
> >>
> >> -rw-r--r-- 1 root root            1478 Dec 21 20:35 DiskDescriptor.xml
> >> -rw------- 1 root root               0 Nov 27 12:33 DiskDescriptor.xml.lck
> >> -rw------- 1 root root 257 447 428 096 Dec 20 07:42 root.hdd
> >> -rw------- 1 root root     376 438 784 Dec 20 09:27 root.hdd.{e66fccca-85cf-4bf2-888d-6669988f1da6}
> >> -rw------- 1 root root     517 996 544 Dec 21 17:49 root.hdd.{f881c603-48cd-4e21-af63-45e49ce715ba}
> >> drwx------ 2 root root            4096 Nov 27 12:34 root.hdd.mnt
> >>
> >> What can we do to compress this down to the actual 2G used?
> >
> > Looks like you did a snapshot, didn't you? In this case only the last
> > delta is compacted.
> >
> > You can try to delete snapshots and compress the disk again.
> >
> >>
> >> 2.6.32-042stab081.5
> >> e2fsprogs-resize2fs-static-1.42.3-3.el6.1.ovz.x86_64
> >> vzctl-4.5.1-1.x86_64
> >> vzkernel-2.6.32-042stab081.5.x86_64
> >> vzctl-core-4.5.1-1.x86_64
> >> vzquota-3.1-1.x86_64
> >> vzstats-0.5.2-1.noarch
> >> ploop-lib-1.9-1.x86_64
> >> ploop-1.9-1.x86_64
> >> _______________________________________________
> >> Users mailing list
> >> Users at openvz.org
> >> https://lists.openvz.org/mailman/listinfo/users