MySQL Backup

#!/bin/bash
USERNAME="root"
PW="pass"
BACKUPDIR=/crew/data/backup
DBDIR=/crew/data/backup/DB
MYSQLDIR=/var/lib/mysql
rm $DBDIR/*.sql
`mv $BACKUPDIR/sql.tar.gz $BACKUPDIR/sql.tar.gz.1`
`mv $BACKUPDIR/sql.md5 $BACKUPDIR/sql.md5.1`
for DB in $MYSQLDIR/*; do
DB=`basename $DB`
mysqldump -c -e -a -B $DB -u $USERNAME -p$PW > $DBDIR/$DB.sql
echo "$DB is dumped..."
done
tar -zvcf $BACKUPDIR/sql.tar.gz $DBDIR 1> /dev/null
rm $DBDIR/*.sql
`/usr/bin/md5sum $BACKUPDIR/sql.tar.gz > $BACKUPDIR/sql.md5`