I use Proxmox 2.2 for making OpenVZ containers.
It ships with a tool called vzdump that can create backups of OpenVZ containers on the fly. It uses snapshot functionality of LVM to create temporary “fork” of filesystem for backup purposes.
Unfortunately it sometimes crashes with one container that performs a lot of disk operations. As far as I know most probably it is because LVM has limited space that it can use for storing changes made to the volume during snapshot.
I’ve tried to increase snapshot size in /etc/vzdump.conf, but then vzdump returns error like
Volume group "pve" has insufficient free space (256 extents): 512 required.
When I type pvdisplay, I got:
me@srv:~# pvdisplay --- Physical volume --- PV Name /dev/md2 VG Name pve PV Size 921.01 GiB / not usable 3.94 MiB Allocatable yes PE Size 4.00 MiB Total PE 235777 Free PE 256 Allocated PE 235521 PV UUID 7w2TSL-Xv76-jkDg-GrfU-AZ0g-dGq4-GLCFoA
Indeed, Free PE value is not too big
How to increase it? Is it possible without stopping services on the server?
You can do one, or both, of two things:
Reduce the amount of space in use by shrinking or removing logical volumes in the volume group.
Add more space to the volume group by adding another physical volume, such as another disk array.
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