Script for easy backup of your /home directory to an external drive utilizing the snapshot capabilities of btrfs.

btrfs-backup.sh

#!/bin/bash

# config
username=user
backupdir="/media/$username/externalDrive"
name=$(date +Backup\ %Y-%m-%d\ %H:%M)
partuuid="3e45a3de-01" # find your partition uuid by running blkid

# check for root permission
if [[ $UID -ne 0 ]]
then
	sudo $0
	exit $?
fi

mkdir -p $backupdir
mount PARTUUID=$partuuid $backupdir
if [ ! -d "$backupdir/lastBackup" ]
then
	echo "$backupdir/lastBackup does not exist!"
	echo "Is the backup drive connected to the pc?"
	read
	exit 1
fi

read -p "Do you want to perform a backup now? (type \"yes\") " yesno
if [ "$yesno" != "yes" ]
then
	exit 2
fi

# temporarily snapshot /home so you can continue working while the backup is running
btrfs subvolume snapshot /home /home/backupSnapshot

# copy to ./lastBackup
rsync -aPEh --delete --stats /home/backupSnapshot/ $backupdir/lastBackup
btrfs subvolume delete /home/backupSnapshot
cd $backupdir
btrfs subvolume snapshot lastBackup "$name"
chown -R $username:$username "$name"
sync
cd /
umount $backupdir && rm -r $backupdir
echo "Backup complete!"
echo "Please unplug the external drive now."
read