Macrium Reflect retention rules provide a powerful and flexible way to manage the lifetime and storage space used by your backups.
Choose how backups are matched, and how retention rules are applied to the target folder
Retention rules are applied to the target folder of the backup by selecting one of two options:
|Similar backup sets in the target folder.|
Disk Images are purged if they contain exactly the same Partitions as the current Image. Partitions are identified using the unique Disk ID stored in sector 0 of the disk and the Partition sector offset. Note: For GPT disks the unique GPT disk GUID is used instead of the Disk ID
For File and Folder backups retention rules are applied according to the File and Folder 'Backup Set Matching' selection.
|All backup sets in the target folder.||All backup sets in the target folder of the same type (Disk Image or File and Folder) are purged according the retention rules.|
Select the age or number of backup types that you wish to keep
|Full||When deleting Full backups all linked incremental and Differential backups in the same backup chain (set) are also deleted This operation will delete the entire backup set.|
|Differential||When deleting Differential backups all linked incremental backups in the same backup chain (set) are also deleted.|
When deleting Incremental backups the integrity of the backup set is maintained by ensuring that the chain is never broken. This is achieved by merging older Incremental backups when required.
In the example below, before retention, there is 1 Full backup, 1 Differential backup and 6 Incremental backups. The retention rules are set to retain 4 incremental backups. After retention, the most recent 4 incremental backups are retained. Deleting the oldest 2 incrementals would cause the backup chain to be invalid as the oldest retained incremental requires the previous 2 incremental backups to complete the chain. To ensure backup integrity the 2 older incremental backups are consolidated with it to create a new incremental backup.
|Create a Synthetic Full if possible|
When purging Incremental backups, if the backup set only contains a Full backup followed by Incremental backups, then this option causes the Full backup to be 'rolled forward' to create a Synthetic Full backup. This is also known as Incremental Forever.
|Run the purge before the backup|
Select this option to run the retention rules before the current backup.
|Delete oldest backup set(s) if less than n GB|
Automatically remove the oldest backup set(s) in the target folder if the free space on the drive drops below the GB threshold.