Here is how I did.
First backup the database and files used in your previous setup, one never knows you might actually need it after the purge...
/usr/bin/mysqldump -aecqQ bacula > bacula_before_purge.sql
and copy the volumes and bsr files.
Stop bacula :
service bacula-director stop service bacula-fd stop service bacula-sd stop
mysql -u root -p drop database bacula; create database bacula; quit
next we need to recreate bacula tables. There's a bacula script to do that, but the file needs to be changed to set the correct database name.
cp /usr/share/bacula-director/make_mysql_tables ~/ vi ~/make_mysql_tables
change XXX_DBNAME_XXX by your bacula database (let's say 'bacula')
save and exit.
then run as root the script
it should have recreated the tables :
mysql -u root -p use bacula; show tables; +------------------+ | Tables_in_bacula | +------------------+ | BaseFiles | | CDImages | | Client | | Counters | | Device | | File | | FileSet | | Filename | | Job | | JobMedia | | Location | | LocationLog | | Log | | Media | | MediaType | | Path | | Pool | | Status | | Storage | | UnsavedFiles | | Version | +------------------+ 21 rows in set (0.00 sec) quit
next you need to delete the existing volume and bsr files.
In my case I just change the location of the bacup (bacula-sd.conf 'Archive Device')
restart your bacula services and run a job to check everything is OK.
service bacula-director start service bacula-fd start service bacula-sd start
Image from http://www.everaldo.com/