The default automatic database backup which VPOP3 performs cycles backup files on a weekly basis. This is performed by saving the backup as a file DBBack-0.dmp on Sunday, DBBack-1.dmp on Monday, etc. The following Sunday, the previous DBBack-0.dmp file is overwritten meaning you have a week's worth of backups available.
This rotation is achieved by using 'replacements' in the backup filename. In the default case, the replacement %w tells VPOP3 to replace that text with the day of week number (0-6), so each day the backup filename is different.
You could have a monthly rotation cycle, by using %d instead of %w. In this case, the backup filename would have the day of month appended, instead of the day of week.
You can use:
- %d to be replaced by the day-of-month number,
- %m to be replaced by the month number,
- %y to be replaced by the year number,
- %h to be replaced by the hour number when the backup started.
You can also use %2 to %9 to use a number which cycles daily from 0 to n-1, for instance %5 will cycle 0, 1, 2, 3, 4, 0, 1, 2, 3 etc
These % replacements can be used anywhere in the filename, including in any directory parts if you wish.
DBBACK.DMP - no rotation, each day's backup overwrites the previous day's backup
DBBACK-%5.DMP - VPOP3 creates 5 backup files called DBBACK-0.DMP to DBBACK-4.DMP, overwriting the backup from 5 days ago
DBBACK-%d-%h.DMP - VPOP3 creates backups with the day of month and hour (24hr) in the name. This can be useful if you do several backups a day and want to keep a lot of old backups
DBBACK-%h.DMP - VPOP3 creates a backup with the hour in the name. This can be useful if you do several backups a day, but want VPOP3 to only keep backups from the last 24 hours.
(The 'DBBACK' text is not mandatory, you could use 'Backup' or 'VPOP3Back' or 'Cantaloupe', or anything you want).