Save Set Staging:
Save set staging is a process of transferring data from one storage medium to another. Staging reduces the time it takes to complete a backup by directing the initial backup to a high performance file type or adv_file device. The data can then be staged to a storage medium, freeing up the disk space. Any volume type, such as Default, Index Archive, or Default Clone, can be staged. Staging is particularly well suited for data that has been backed up on file type or adv_file devices. Staging allows the occupied disk space on file type or adv_file devices to be reclaimed so that the disk space can be used for other purposes. Use staging to move the data to more permanent storage, such as an optical or tape volume, or even another, lower-priority device. Staging also allows data to be moved off the device outside the backup period, ensuring that sufficient disk space is available for the next backup session. Additional licencing may be required.
You can create, edit, and delete staging policies as you can for other NetWorker resources. As part of the client setup, the use of a staging device can be selected for each pool (or set of pools) for backup, archive, and migration. The files are retained for the specified time in the disk staging pool before being moved to a tape device or optical disk. Any number of devices can be in the staging pool, and a save set can be staged as many times as required, for example to disk, to optical disk, to a local tape device, and to a remote tape device. Also, a volume can be staged to a second volume, and then that data on the second volume can be staged back to the first volume.
The staging process is driven by one of the following events:
- As part of an automatic process, such as keeping the save set for 30 days on the staging device before staging the data to the next device.
- As part of an event driven process, such as when available space in the staging pool drops below a set threshold. When this happens, the oldest save sets are moved first, until available space reaches the upper threshold that has been set.
- As part of an administrator initiated process, such as allowing the administrator to either reset the threshold and kick off staging or manually select save sets to stage.
When you enable a staging policy, the NetWorker server creates a clone of the save set you specify on a clone volume of the medium you specify. After the save set is staged, the save set is deleted from the filesystem to free the space.
The NetWorker server tracks the location of the save set in the media database. The retention policy for the save set does not change when the data is staged. If the file type volume is on a storage node that is running NetWorker software 6.1 or earlier, the tape is not automatically marked appendable after the staging operation.