Cloning and Data Tracking Information

The clone operation does not insert entries into the client file index. Cloned save sets are only tracked through the media database. During a clone operation, the location of a cloned save set is added to the existing save set entry in the media database. That is, each save set clone shares the same ssid as the source save set. All characteristics that are true for the source save set are also true for the clone save set. If the source save sets are still browsable, the clone status is also browsable. If the source save sets have passed their browse policies, the clone status is recoverable.

Volumes that belong to a clone pool are also tracked through volume entries in the media database. The fact that all save sets share the same media database save set entry has implications for the following actions, which are executed on a "per save set basis" and not on a "per volume" basis:

• Changing the mode of a cloned volume (of save sets)

• Purging a volume (of save sets) from the client file index

• Deleting a volume (of save set locations) from the media database

If you manually change the mode of a cloned volume to recyc with the intent of reusing a particular clone volume, be aware that the mode of a volume only changes to recyclable when all the save sets on that volume are recyclable. Therefore, when the mode of the volume changes to recyc, you effectively change the status of all save sets on the clone volume to recyc. Because the save sets share the same entry in the media database, there is no distinction between "original" and "clone" save sets. The end result is that all the save sets that reside on the now recyclable volume or on any other volume become candidates for immediate recycling.

To prevent inadvertent loss of data, if you want to reuse a particular clone volume and still protect the instances of a save set that exist on other volumes, first change the mode of the volumes to be protected to man_recyc. This means that Backup cannot automatically recycle the volume. Then, you can safely change the volume that you intend for reuse to mode recyc.

Similarly, if you purge a clone volume, you effectively remove from the client file index all file entries associated with all save sets that reside (in whole or in part) on the particular clone volume.

If you delete a clone volume, the nsrim index management program locates the entry in the media database for each save set that resides on the clone volume. From the entry, the nsrim program marks for deletion the information about the location of one of the save set clones from the entry. This action is performed for each save set entry. In addition, nsrim marks the entry for the particular clone volume (identified by its volume ID number) for deletion from the database.