#!/bin/bash

# sparse and compress guest image
# use ramdisk to spare ssd writes (note the amount of RAM needed)

date +%F_%T  \
 && \
cd /var/lib/libvirt/images/  \
 && \
mount -t tmpfs -o size=32g tmpfs /mnt  \
 && \
mkdir /mnt/tmp  \
 && \
TMPDIR=/mnt/tmp virt-sparsify arch.qcow2 /mnt/tmp.qcow2  \
 && \
sync  \
 && \
qemu-img convert -O qcow2 -c /mnt/tmp.qcow2 arch.qcow2  \
 && \
sync  \
 && \
ls -lh  \
 && \
umount /mnt  \
 && \
date +%F_%T