QEMU+KVM, reclaim disk space

Tue, 17 Nov 2015 11:06:29 +0000

After some time qcow2 images tend -especially after taking snapshots- to grow bigger and bigger, even bigger than the maximum size specified at creation time.
QEMU provides a tool called virt-sparsify (install libguestfs-tools package in CentOS 7) that can effectively make a virtual machine disk thin provisioned (space is not preallocated, only the actual space needed is used).
virt-sparsify has a nice number of options, the most interesting one is --in-place, it tells QEMU to shrink the volume in place without requiring any addition space.

QEMU+KVM on nagg.eu

QEMU+KVM, reclaim disk space