Parallel Roll Forward from Tape (UNIX)
To roll forward a multi-location database from tape in parallel, specify the devices to be used in the From Tape Device edit control. For example, the following tape device can be specified:
/dev/rmt/0m,/dev/rmt/1m
This restores one location per tape--the first location can be restored from device 0m; the second location can be restored from device 1M. The third location can be restored from whichever device is finished first. The remaining locations can be restored from the next free device. The operator is prompted to insert the numbered tape into the free device.
Some points to be aware of when performing parallel roll forward from tape include:
• Recovery does not have to be in parallel if a checkpoint was done in parallel.
• Recovery can be in parallel if a checkpoint was not done in parallel.
• Each tape label must include the checkpoint number, database name, and location number.
• Each tape device must be the same medium, that is, all 4mm or all 8mm; mixing is not permitted.
• The maximum number of devices that can be used is limited by the system’s input and output bandwidth.