[djbaxter]

Yes, or at least to keep only the last 7 backups. Someone else gave me this solution a while back in this thread.

AdminCP >> Settings >> Options >> vBulletin Automatic Backup

Combine Files
Set to yes to combine all tables into one backup file. = Yes

Date Format
Backup file date format (See http://uk.php.net/date). = N

Files Prefix
Backup files prefix, this is applied to all files. = FORUMNAME

GZip Files
Attempt to GZip the backup files after they have been saved. This may or may not work depending on your server environment. = Yes

What this does is create a series of backups with the format

FORUMNAME-digit-Full-Backup.sql.gz

where digit is the number of the day of the week, i.e., 1 through 7.

Once that change is made to options, as the backups are created they are saved with that format. If the filename doesn't exist, it is created. If the filename already exists, it is overwritten by the new backup. Thus, you always have the latest 7 days of backups and no more.

This works perfectly. I've been using it for several months now.