Backup all VM's in KVM

kvm-backup.sh

#!/bin/bash

# This script creates a backup for all running libvirtd domains on the host it's
# run on.
#
# I created this script because I needed a lightweight backup solution for a pure libvirtd
# virtual machine host.
#
# You can use / modify this script however you like. All I ask is that if you find a bug or something
# very wrong (or if you find a massive upgrade point) is that you let me know!

# If this is set to 1 this script will
# output a lot more, for debugging
VERBOSE=1

# Set the script language to English
LANG=en_US.UTF-8

# Define the script name for use in the journal
SCRIPTNAME=kvm-backup-test

# List the domains
DOMAINS="$(virsh list| tail -n +3 | awk '{print $2}')"

# Loop over the domains and start the backup
# cycle.
for DOMAIN in $DOMAINS; do

	# Check if the ignore backup config file (/etc/kvm-backup.ignore) exists
	# and parse it if required.
	if [[ -f /etc/kvm-backup.ignore ]]; then
		if grep -Fxq "$DOMAIN" /etc/kvm-backup.ignore; then
			systemd-cat -t $SCRIPTNAME echo "Ignoring domain '$DOMAIN' per config"
			continue
		fi
	fi

	systemd-cat -t $SCRIPTNAME echo "Starting backup for domain '$DOMAIN'"

	# Generate the backup folder URI
	# Lifed from Aaron Studer's revision of my original script, see
	# https://gist.github.com/aaronstuder/f481f4b9ff270f9ddcd098f283dc71cd#file-kvm-backup-sh-L24
	# for source
	BACKUPFOLDER="/mnt/backups/$DOMAIN/$(date +%Y)/$(date +%m)/$(date +%d)/"

	if [[ $VERBOSE -eq 1 ]]; then
		systemd-cat -t $SCRIPTNAME echo "Backup folder URI is '$BACKUPFOLDER'"
	fi

	if [[ ! -d $BACKUPFOLDER ]]; then
		mkdir -p $BACKUPFOLDER
	fi

	# Get VM disk info
	DISKINFO=$(virsh domblklist $DOMAIN --details | grep disk | awk '{print $3,$4}')

	# Get the disk type (sda, vda, etc)
	DISKTYPE=$(echo $DISKINFO | awk '{print $1}')

	# Get the disk path
	DISKPATH=$(echo $DISKINFO | awk '{print $2}')

	if [[ $VERBOSE -eq 1 ]]; then
		systemd-cat -t $SCRIPTNAME echo "Disk info is '$DISKINFO', disk type is '$DISKTYPE', disk path is '$DISKPATH'"
	fi

	# Do the snapshot
	if [[ $VERBOSE -eq 1 ]]; then
		systemd-cat -t $SCRIPTNAME virsh snapshot-create-as --domain $DOMAIN --name "snapshot" --no-metadata --atomic --disk-only --diskspec $DISKTYPE,snapshot=external
	else
		virsh snapshot-create-as --domain $DOMAIN --name "snapshot" --no-metadata --atomic --disk-only --diskspec $DISKTYPE,snapshot=external > /dev/null
	fi

	if [[ $? -ne 0 ]]; then
		systemd-cat -t $SCRIPTNAME echo "Failed to create snapshot for domain '$DOMAIN'"
	fi

	# Copy the disk image
	DISKPATHBASENAME=$(basename $DISKPATH)
	cp $DISKPATH $BACKUPFOLDER/$DISKPATHBASENAME

	if [[ $VERBOSE -eq 1 ]]; then
		systemd-cat -t $SCRIPTNAME echo "Done copying the disk for domain '$DOMAIN'"
	fi

	# Get the backup disk (sda, vda, etc) path now so we can
	# remove it later
	BACKUPDISKPATH=$(virsh domblklist $DOMAIN --details | grep disk | awk '{print $4}')

	if [[ $VERBOSE -eq 1 ]]; then
		systemd-cat -t $SCRIPTNAME echo "Backup disk path is '$BACKUPDISKPATH'"
	fi

	# merge the changes back
	if [[ $VERBOSE -eq 1 ]]; then
		systemd-cat -t $SCRIPTNAME virsh blockcommit $DOMAIN $DISKTYPE --active --pivot
	else
		virsh blockcommit $DOMAIN $DISKTYPE --active --pivot > /dev/null
	fi

	if [[ $? -ne 0 ]]; then
		systemd-cat -t $SCRIPTNAME echo "Could not merge changed for disk of type '$DISKTYPE' on domain '$DOMAIN'. VM *may* be in an invalid state."
	else
		rm -f $BACKUPDISKPATH

		if [[ $VERBOSE -eq 1 ]]; then
			systemd-cat -t $SCRIPTNAME  echo "Removed backup disk for domain '$DOMAIN'"
		fi
	fi

	# Dump the VM xml
	virsh dumpxml $DOMAIN > $BACKUPFOLDER/$DOMAIN.xml

	if [[ $? -ne -0 ]]; then
		systemd-cat -t $SCRIPTNAME echo "Could not dump XML for domain '$DOMAIN'"
	fi

	systemd-cat -t $SCRIPTNAME echo "Finished backup of domain '$DOMAIN'"

done

exit 0

"virsh list" shows only running VMs. Well, maybe we do not need to snapshot shut off VMs, but we need to backup 'em anyway, eh?
So, "virsh list --al" and then some checks is VM running (snapshot/backup) or shut off (backup only).

"virsh list" shows only running VMs. Well, maybe we do not need to snapshot shut off VMs, but we need to backup 'em anyway, eh? So, "virsh list --al" and then some checks is VM running (snapshot/backup) or shut off (backup only).

As the literal first line of this scripts says:

This script creates a backup for all running libvirtd domains on the host it's
run on.