kvm | linux | shrink sparse disk using zerofree

Install zerofree edit your fstab, set your root drive to RO like /dev/vda1 / ext2 ro 0 1 Halt your system # halt -p Start your system into the grub menu, then select rescue mode, then drop to root shell Run zerofree like # zerofree /dev/vda1 Remount your root drive RW # mount -o remount,rw […]

kvm | qemu | qcow2 dynamic/sparse disk allocation problem | shrink sparse qcow2 disks howto

In some recent qemu versions there is a problem while creating sparse disks using the virt-manager. Normally the qcow2 format always allocates space dynamically (sparse), but some qemu versions fail at this, they create disks with full expected size. Solution: Create your disks manually: Shrinking existing images: # mv disk.qcow2 disk.qcow2.orig # qemu-img convert -O […]