When the storage media is re-writable, and the user has the right folder privileges, Genie Backup Manager (GBM) can be set to delete old backup files created by the backup job, to save space. The way purging old backups works varies depending on the backup type used. Purging is not supported when Mirror Backup is used.
To set GBM to purge old backup files created by a backup job:
- From the left menu in the Backup Wizard, select Settings.
- Click Purge Settings.
- Select one of the following options:
- Keep old backups: Do not delete old backups.
- Keep only last X backups: Keep only the last X backup files and delete files produced by older backups.
- Keep old backups for a period of X days: Delete any backup file older than X days.
Backup Sets
To understand how purging works in Genie Backup Manager, the user needs to be familiar with the concept of Backup Sets. For the purpose of this help documentation, a backup set is the minimum collection of backup files – or folders, in the case of backup without compression – that are needed to successfully perform a restore. For example, if the user wishes to restore files that were backed up using an incremental backup job on March 23rd, then every backup file created by this backup job since that date and back to the most recent full backup before that date should be present and are considered a backup set.
Purging works with backup sets and not backup runs. if the user chooses to “keep the last 5 backups”, that means that Genie Backup Manager will always keep the most recent 5 backup sets created by that job.
Purging with Full Backup
Full backup copies all the selected files each time the backup is performed. Each time a full backup is performed, a new backup set is created, and a bracketed number after the backup job name is incremented by one, to denote the backup run number.
Since each backup run creates a backup set, keeping the last X backup sets means keeping the backup files produced by the most recent X backup runs.
Example:
A full backup is performed, job name is “My_backup”, and purging option selected is “keep only last 4 backups”.
| 1st run | My_backup.gbp is created |
| 2nd run | My_backup(1).gbp is created |
| 3rd run | My_backup(2).gbp is created |
| 4th run | My_backup(3).gbp is created |
| 5th run | My_backup(4).gbp is created and My backup.gbp is deleted |
| 6th run | My_backup(5).gbp is created and My Backup(1).gbp is deleted |
| 7th run | My_backup(6).gbp is created and My Backup(2).gbp is deleted |
Purging with Incremental Backup
During incremental backups, the first backup run performed after the backup job is created is a Full backup, subsequent backup runs are all incremental until the user elects to reset the backup job to full, either manually or automatically using the “Limiting increments” feature. GBM treats each full backup and all subsequent increments until the next full run as a complete backup set.
For each backup run that is performed, a number after the backup job name is incremented by one, when backup is switched to full, that number is reset and another bracketed number is incremented by one to denote the number of full backups performed since the backup job was created.
When purging is selected, backup rotation is forced, which means that after a certain number of incremental backups, Genie Backup Manager will automatically reset the backup type to full for one backup run, then performs another set of incremental backup runs, then resets to full again, and so on.
If the user enables purging with the option to “Keep only last X backups”, Genie Backup Manager will reset backup type to full “full” X time, and on the X+1 run, it will delete the oldest backup set.
Example:
An incremental backup is performed.
- Job name: My_backup
- Purging option: keep only last 3 backups
- Backup rotation: 2 increments.
* Bold denotes the creation of a new backup set.
| 1st run | My_backup.gbp is created (Full backup) | Backup Set |
| 2nd run | My_backup.0.gbp is created (increment) | |
| 3rd run | My_backup.1.gbp is created (increment). | |
| 4th run | My_backup(1).gbp is created (Full backup) | Backup Set |
| 5th run | My_backup(1).0.gbp is created (increment) | |
| 6th run | My_backup(1).1.gbp is created (increment) | |
| 7th run | My_backup(2).gbp is created (Full backup) | Backup Set |
| 8th run | My_backup(2).0.gbp is created (increment) | |
| 9th run | My_backup(2).1.gbp is created (increment) | |
| 10th run | My_backup(3).gbp is created (Full). My_backup.gbp, My_backup.0.gbp & My_backup.1.gbp are deleted | Backup Set |
| 11th run | My_backup(3).0.gbp is created (increment) | |
| 12th run | My_backup(3).1.gbp is created (increment) | |
| 13th run | My_backup(4).gbp is created (Full). My_backup(1).gbp, My_backup(1).0.gbp & My_backup(1).1.gbp are deleted |
Purging with Differential Backup
During differential backups, the first backup run performed after the backup job is created is a full backup, subsequent backup runs are all differential until the user elects to reset the backup job to full, either manually or automatically using the “Limiting increments” feature. Each differential backup along with the most recent full backup combined form a standalone backup set. Backup files produced in between those two backups can be deleted safely.
Purging with “Limit increments” option enabled
If purging was selected and the “Limit increments” option was enabled for X increments. Genie Backup Manager will automatically reset the backup type to full after every X differential backup runs. Purging in this case will treat each full backup run with all subsequent consecutive differential runs as a backup set, and purging will work exactly like in the case of incremental backup.
Purging with “Limit increments” option disabled
If purging is selected with the “limit increments” option disabled, Genie Backup Manager will treat each differential backup run along with the most recent full backup as a standalone backup set. Thus, the option to “Keep only last X backups” means that only the full backup run, the last differential backup, and the most recent X intermediate backups are kept.
Example:
A differential backup is performed.
- Job name: My_backup
- Purging option: keep only last 3 backups
- Limit increments: disabled
| 1st run | My_backup.gbp is created (Full backup) |
| 2nd run | My_backup.0.gbp is created (Differential) |
| 3rd run | My_backup.1.gbp is created (Differential) |
| 4th run | My_backup.2.gbp is created (Differential) |
| 5th run | My_backup.3.gbp is created (Differential). My_backup.0.gbp is deleted. |
| 6th run | My_backup.4.gbp is created (Differential). My_backup.1.gbp is deleted. |
| 7th run | My_backup.5.gbp is created (Differential). My_backup.2.gbp is deleted. |
| 8th run | My_backup.6.gbp is created (Differential). My_backup.3.gbp is deleted. |
Rotating Backups
When increment or differential backup is used, the user can set GBM to automatically switch to full backup after a specific number of increments. Each full backup and its subsequent increments are treated by GBM as one backup set, enabling the user to purge old backup sets safely.
To set GBM to limit the number of increments for each backup set:
From the left menu in the Backup Wizard, select Settings
- Click Purge Settings.
- Select the Limit increments option.
- In Number of increments, type the number of increments you wish GBM to perform before switching to full backup .
Purging is not supported in the following cases:
- When the backup is spanned to multiple locations.
- Backing up using the built-in CD/DVD burner.
- FTP and Amazon S3 backups.
Applies To: Genie Backup Manager (GBM).
