#!/bin/sh
#
# Backup of all filesystems.
# Backup level specified as argument.
#

# get backup level from command line; defaults to 0
BACKUP_LEVEL=${1:-0}

# backup device: non-rewinding 4 Gb SCSI tape 
export TAPE=/dev/nrst0
TAPE_LENGTH=4194304

# backup command and options
BACKUP_CMD=/sbin/dump
BACKUP_OPTS="${BACKUP_LEVEL}uB $TAPE_LENGTH"

# command to flush filesystem cache
SYNC_CMD=/bin/sync

# filesystems table
FSTAB=/etc/fstab

# get all dumpable filesystems 
FILESYSTEMS=`grep -v '^#' $FSTAB | awk '$5 != 0 { print $2 }'`

# can't login when this file exists
NOLOGIN=/etc/nologin


# prevent logins
echo "SYSTEM BACKUP IN PROGRESS - Please try again later" > $NOLOGIN

# allow logins again on exit/failure
trap "rm $NOLOGIN ; exit" 0 1 2 15


for fs in $FILESYSTEMS
do
   # flush filesystem cache
   $SYNC_CMD

   # do it
   $BACKUP_CMD $BACKUP_OPTS $fs

   [ $? = 0 ] || { echo "BACKUP FAILED!!!" >&2; exit 1; }
done


# eject tape
mt rewoffl && echo "Backup successful; tape ejected"