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## Reclaim threshold 

The reclaim threshold directly affects how much data is moved during each reclaim operation. The default setting is 35% for each pool. Clients tend to raise this threshold too high because they want to store more data on their stacked volumes. The result is that reclaim operations must move larger amounts of data and use drive resources that are needed for recalls and premigration. After a reclaim task is started, it does not free its back-end drives until the volume being reclaimed is empty. 

The reclaim threshold and the amount of data that must be moved (depending on the stacked tape capacity and the reclaim percentage) are listed in Table 12-3. When the threshold is reduced from 40% to 20%, only half of the data must be reclaimed. This change reduces by half the time and resources that are needed for reclaim. However, it raises the needed number of backend cartridges and slots in the library. 

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## Inhibit Reclaim schedule 

Use the Inhibit Reclaim schedule to inhibit reclaims during your busy periods, which leaves back-end drives available for recalls and premigrates tasks. Generally, start the inhibit 60 minutes before the heavy workload period. This setting allows any started reclaim tasks to complete before the heavy workload period. 

## Adjusting the maximum number of reclaim tasks 

Reclaim operations use two back-end drives per task and CPU cycles. For this reason, use the Inhibit Reclaim schedule to turn off reclaim operations during heavy production periods. 

When reclaim operations are not inhibited, you might want to limit the number of reclaim tasks. For example, moderate host I/O during the uninhibited period and reclaim might use too many back-end drives, CPU cycles, or both. 

By using the Host Library Request  command, you can limit the number of reclaim tasks in the TS7700T. The second keyword RECLAIM  can be used along with the third keyword of RCLMMAX . This expansion applies only to the TS7700T. Also, the Inhibit Reclaim schedule is still acknowledged. 

