BACKDS command: Backing up a specific data set

The BACKDS command creates a backup version of a specific data set. When you enter the BACKDS command, DFSMShsm does not check whether the data set has changed or has met the requirement for frequency of backup. When DFSMShsm processes a BACKDS command, it stores the backup version on either tape or the ML1 volume with the most available space.

Note: If the size of a data set that is targeted to DASD exceeds the free space on the ML1 volume having the most free space, then the data set backup fails. If there is no overflow ML1 volume available or the data set does not qualify for placement on an overflow ML1 volume, then the data set backup fails.

You can issue a BACKDS command for the following:

An SMS-managed data set (if allowed by its management class).
A data set that resides on a level 0 volume.
A migrated data set currently residing on a migration level 1 volume.
An uncataloged data set (DFSMShsm is used as the datamover).
A user data set that resides on a migration level 1 or a DASD migration level 2 volume. We do not recommend that users directly allocate data sets on migration volumes.

Regardless of the status or location of the data set, the volume containing the data set must be mounted and online, or the command fails.

When you want to back up an uncataloged data set, you must specify the volume serial number of the volume that contains the data set. In addition, you must specify the type of unit of the volume specified.

Note: If you specify a data set currently migrated to a migration level 2 volume, DFSMShsm does not back up the data set.