The cPanel & WHM system have a particular retention behavior that they show. This can be edited in WHM’s Backup Configuration interface (WHM >> Home >> Backup >> Backup Configuration) accordingly.
This system has two retention modes, namely, the default backup retention behavior and the strictly-enforced retention ensuring successful backups, set in WHM’s Backup Configuration interface. But, relief is that the backup will keep all the backups (successful and failed backups) no matter what happens.
If by chance your server has limited space for backups, then you can enable strictly-enforced retention. By this, the server keeps one successful backup and deletes all others which are extending the space limit. For enabling this, you can select the Strictly enforce retention in WHM’s Backup Configuration interface. You can also make your system notify you about every backup, be it successful or not. You can read our Contact Manager documentation for more information.
The system tends to delete the oldest backup, as and when cPanel and WHM completes a particular backup. However, if suppose a recent backup fails, then the system will not delete the oldest backup, it will keep all of them and will continue to keep the oldest backups to ensure that one successful backup remains in the system. When finally system will get a successful backup, it will delete the oldest backups to maintain the limit, as now they have got a recent successful backup.
When you enable the strictly-enforced retention, cPanel & WHM will delete the oldest backup as and when the system will get a complete successful backup. But, if the system-generated backup fails, then the system will keep the failed backup and automatically delete the oldest backup, and will not continue to keep the oldest backup. It will just keep the last successful backup. This particular behavior is kept to ensure that system should have at least a single successful backup stored in itself.
Again, when a recent backup gets successful, the system will delete the oldest backups at once and keep these new backup.
All information on backup retention behavior is outlined in this review.