-
-
Save bretton/244a6f7e3b256f17dd1ed1e36e1cd7ea to your computer and use it in GitHub Desktop.
I use this script to backup my QEMU/KVM/libVirt virtual machines. The script requires KVM 2.1+ since it uses the live blockcommit mode. This means the data in the snapshot disk is rolled back into the original instead of the other way around. Script does NOT handle spaces in paths.
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
#!/bin/bash | |
# | |
BACKUPDEST="$1" | |
DOMAIN="$2" | |
MAXBACKUPS="$3" | |
if [ -z "$BACKUPDEST" -o -z "$DOMAIN" ]; then | |
echo "Usage: ./vm-backup <backup-folder> <domain> [max-backups]" | |
exit 1 | |
fi | |
if [ -z "$MAXBACKUPS" ]; then | |
MAXBACKUPS=6 | |
fi | |
echo "Beginning backup for $DOMAIN" | |
# | |
# Generate the backup path | |
# | |
BACKUPDATE=`date "+%Y-%m-%d"` | |
BACKUPDOMAIN="$BACKUPDEST/$DOMAIN" | |
BACKUP="$BACKUPDOMAIN/$BACKUPDATE" | |
mkdir -p "$BACKUP" | |
# | |
# Get the list of targets (disks) and the image paths. | |
# | |
TARGETS=`virsh domblklist "$DOMAIN" --details | grep ^file | grep -v 'cdrom' | grep -v 'floppy' | awk '{print $3}'` | |
IMAGES=`virsh domblklist "$DOMAIN" --details | grep ^file | grep -v 'cdrom' | grep -v 'floppy' | awk '{print $4}'` | |
# | |
# Create the snapshot. | |
# | |
DISKSPEC="" | |
for t in $TARGETS; do | |
DISKSPEC="$DISKSPEC --diskspec $t,snapshot=external" | |
done | |
virsh snapshot-create-as --domain "$DOMAIN" --name backup --no-metadata \ | |
--atomic --disk-only $DISKSPEC >/dev/null | |
if [ $? -ne 0 ]; then | |
echo "Failed to create snapshot for $DOMAIN" | |
exit 1 | |
fi | |
# | |
# Copy disk images | |
# | |
for t in $IMAGES; do | |
NAME=`basename "$t"` | |
cp "$t" "$BACKUP"/"$NAME" | |
done | |
# | |
# Merge changes back. | |
# | |
BACKUPIMAGES=`virsh domblklist "$DOMAIN" --details | grep ^file | grep -v 'cdrom' | grep -v 'floppy' | awk '{print $4}'` | |
for t in $TARGETS; do | |
virsh blockcommit "$DOMAIN" "$t" --active --pivot >/dev/null | |
if [ $? -ne 0 ]; then | |
echo "Could not merge changes for disk $t of $DOMAIN. VM may be in invalid state." | |
exit 1 | |
fi | |
done | |
# | |
# Cleanup left over backup images. | |
# | |
for t in $BACKUPIMAGES; do | |
rm -f "$t" | |
done | |
# | |
# Dump the configuration information. | |
# | |
virsh dumpxml "$DOMAIN" >"$BACKUP/$DOMAIN.xml" | |
# | |
# Cleanup older backups. | |
# | |
LIST=`ls -r1 "$BACKUPDOMAIN" | grep -E '^[0-9]{4}-[0-9]{2}-[0-9]{2}\.[0-9]+$'` | |
i=1 | |
for b in $LIST; do | |
if [ $i -gt "$MAXBACKUPS" ]; then | |
echo "Removing old backup "`basename $b` | |
rm -rf "$BACKUPDOMAIN/$b" | |
fi | |
i=$[$i+1] | |
done | |
echo "Finished backup" | |
echo "" |
Works a treat on SSD servers, fails on servers with spinning disks and high IO.
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
File changed to drop minutes & seconds from date.
Wrapper script mentioned at https://gist.github.com/cabal95/e36c06e716d3328b512b#gistcomment-2015722 is used as well