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. Reclaim threshold 8464ch12_Performance.fm Draft Document for Review February 7, 2020 4:43 pm Table 12-3 Reclaim threshold by cartridge capacity Cartridge capacity Reclaim threshold 10% 20% 30% 40% 300 GB 30 GB 60 GB 90 GB 120 GB 500 GB 50 GB 100 GB 150 GB 200 GB 640 GB 64 GB 128 GB 192 GB 256 GB 700 GB 70 GB 140 GB 210 GB 280 GB 1000 GB 100 GB 200 GB 300 GB 400 GB 4000 GB 400 GB 800 GB 1200 GB 1600 GB 10000 GB 1000 GB 2000 GB 30200 GB 4000 GB Inhibit Reclaim schedule Adjusting the maximum number of reclaim tasks 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.  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.  732  IBM TS7700 Release 5.0 Guide