gistfile1.bash

#!/bin/bash

# config
SOURCES="/data /home/senko"
BACKUP_DIR="/backup/mypc"

# abort if any of the commands fail
set -e

todays=$(date +'%Y-%m-%d') # nicely sortable names for backups
last=$(ls -r | head -1)
to_delete=$(ls -r | tail -n +7) # will keep the last 6 backups

cd $BACKUP_DIR
ionice -c 3 nice -n +19 rsync -aq \
    --link-dest=${BACKUP_DIR}/${last} $SOURCES $BACKUP_DIR/${todays}

# now we're safe to remove the old one(s)
[ -z "$to_delete" ] || rm -rf $to_delete