Retention Policies

In this article

    A retention policy defines for how long Veeam Backup & Replication must store restore points for VM replicas. Veeam Backup & Replication offers two retention policy schemes:

    Long-term Retention

    Veeam Backup & Replication retains long-term restore points for the number of days specified in CDP policy settings. When the retention period is exceeded, Veeam Backup & Replication transforms the replication chain in the following way. The example shows how long-term retention works for a VM replica with one virtual disk.

    1. Veeam Backup & Replication checks whether the replication chain contains outdated long-term restore points.
    2. If an outdated restore point exists, Veeam Backup & Replication rebuilds the file that contains data for the base disk (<disk_name>-flat.vmdk) to include data of the file that contains data for the delta disk (<disk_name>-<index>.vmdk). To do that, Veeam Backup & Replication commits into the base disk file data from the earliest delta disk file. This way, the base disk file ‘moves’ forward in the replication chain.

    Retention Policies 

    1. Veeam Backup & Replication removes the earliest delta disk file from the chain as redundant — this data has already been committed into the base disk file.

    Retention Policies 

    Short-term Retention

    Veeam Backup & Replication retains short-term restore points for the number of hours specified in CDP policy settings. When the retention period is exceeded, Veeam Backup & Replication transforms the replication chain in the following way. The example shows how short-term retention works for a VM replica with one virtual disk.

    1. Veeam Backup & Replication checks whether the replication chain contains outdated short-term restore points.
    2. If an outdated restore point exists, Veeam Backup & Replication commits data for the restore point from the transaction log file (.tlog or .tlog.vmdk for VSAN and VVOL) into the nearest delta or base disk file (<disk_name>-flat.vmdk or <disk_name>-<index>.vmdk).
    3. If the transaction log file does not contain data for further restore points, Veeam Backup & Replication deletes the transaction log file as redundant — its data has already been committed into the base or delta disk file.

    Note

    Veeam Backup & Replication can store short-term restore points for a longer period than specified in the short-term retention policy. This period is maximum 25% longer.