Resize QCOW2 disk image

Wed, 05 Dec 2018 00:00:00 +0000

QCOW2 disk images can be easily grown using libvirt command line utils.
Unfortunately it isn’t possible to grow QCOW2 images in-place or online.
First of all, power off the virtual machine, grow the file and make a copy of it:


$ qemu-img resize image.qcow2 +200G
$ cp image.qcow2 image-new.qcow2

Identify the specific partion you intend to grow:


$ virt-filesystems -a image.qcow2 -l
Name Type VFS Label Size Parent
/dev/sda1 filesystem ext4 - 536870912 -
/dev/sda3 filesystem xfs - 45885612000 -

Expand the actual partition:

Defragment XFS file system

Wed, 20 Jan 2016 18:18:18 +0000

XFS just like EXT4 (I wrote a post about it last year) supports online defragmentation, to manage those volumes on CentOS and Fedora xfsprogs package is needed.
Fragmentation level of XFS volumes can be checked with the command:

[root@CentOS ~]$ xfs_db -c frag -r /dev/sdb1
actual 4491, ideal 4006, fragmentation factor 10.80%

To perform online defragmentation of XFS volumes run the following command:

XFS on nagg.eu

Resize QCOW2 disk image

Defragment XFS file system