Backup using tar

Example script to backup the /etc and /u folder.

databackup.sh

#!/bin/bash
# databackup.sh backup script

TIMECODE=`date +%Y%m%d`
LASTFULL_REFERENCE=/etc/LASTFULL_REFERENCE
TARPATH=/mnt/backup/tarfiles
MIRRORPATH=/mnt/backup/mirror

do_fail() {
     # email the admin about the failure
     echo "$1"
     echo "$1" | mail -s "Backup Error Alert" backup.alert@example.com
     logger -t databackup "$1"
     umount /mnt/backup
     exit 1
}

do_ok() {
     # email the admin about the success
     echo "$1"
     echo "$1" | mail -s "Backup OK" backup.alert@example.com
     logger -t databackup "$1"
     umount /mnt/backup
     exit 0
}

# sanity check: backup vol mounted?
[[ -d $TARPATH ]] ||  mount /mnt/backup
[[ -d $TARPATH ]] ||  do_fail "Backup volume not mounted!"


case "${1:-''}" in
  
  'full')
    # full backup
    echo $TIMECODE > $LASTFULL_REFERENCE
    
    tar zPcf $TARPATH/etc-full-$TIMECODE.tgz /etc ; r=$?
    [[ "$r" = "2" ]] && do_fail "Full Backup failed for /etc"
    
    tar zPcf $TARPATH/u-full-$TIMECODE.tgz /u ; r=$?
    [[ "$r" = "2" ]] && do_fail "Full Backup failed for /u"
    
    do_ok "Full Backup completed successfully."
    ;;
  
  'diff')  
    # differential backup
    [[ -f $LASTFULL_REFERENCE ]] || do_fail "LASTFULL_REFERENCE file not found!"
     
    echo $TIMECODE > /etc/DIFF_DUMMY
    find /etc -newer $LASTFULL_REFERENCE -type f -print | tar zPcf $TARPATH/etc-diff-$TIMECODE.tgz -T - ; r=$?
    [[ "$r" = "2" ]] && do_fail "Diff Backup failed for /etc."
    
    echo $TIMECODE > /u/DIFF_DUMMY
    find /u -newer $LASTFULL_REFERENCE -type f -print | tar zPcf $TARPATH/u-diff-$TIMECODE.tgz -T - ; r=$?
    [[ "$r" = "2" ]] && do_fail "Diff Backup failed for /u."  
    
    do_ok "Differential Backup completed successfully."  
    ;;
  
  'mirror')
    # mirror using rsync, with IO bandwidth limit of 5MB/s :
    rsync -ax --delete-after --bwlimit=5000 --stats /etc /u $MIRRORPATH/ ; r=$?
    [[ ! "$r" = "0" ]] && do_fail "Mirror Backup failed!"  
    
    do_ok "Mirror Backup completed successfully."  
    ;;
    
  'purge')
    # purge old tar files
    /usr/sbin/tmpwatch -m $((24*14)) $TARPATH ; r=$? 
    [[ ! "$r" = "0" ]] && do_fail "Old backup files purge failed!"  
    
    do_ok "Purge of old backup files completed successfully."    
    ;;
  
  *)
    echo "Usage: databackup.sh full|diff|mirror|purge"
    exit 1
    ;;
  
esac

# full backup every sunday morning
6 0 * * 7 root /usr/local/bin/databackup.sh full  > /var/log/databackup.log 2>&1

# diff backup other days
6 0 * * 1-6 root /usr/local/bin/databackup.sh diff  > /var/log/databackup.log 2>&1

# mirror every day
6 22 * * * root /usr/local/bin/databackup.sh mirror > /var/log/databackup.log 2>&1

# purge old tar files everyday
4 0 * * * root /usr/local/bin/databackup.sh purge