– Days Before Secure Data Erase: The number of days that a physical volume that is a candidate for Secure Data Erase can remain in the pool without access to a physical stacked volume. Each stacked physical volume possesses a timer for this purpose. This timer is reset when a virtual volume on the stacked physical volume is accessed. Secure Data Erase occurs later, based on an internal schedule. Secure Data Erase renders all data on a physical stacked volume inaccessible. The valid range of possible values is 1 - 365. Clearing the check box deactivates this function. 

– Days Without Access: The number of days that a determined pool can stay without being accessed for a recall. When a physical volume reaches that number of days without being accessed, it is set as a candidate for reclamation. Each physical stacked volume has a timer for this purpose, which is reset when a virtual volume is accessed. The reclamation occurs later, based on an internal schedule. The valid range of possible values is 1 - 365. Clearing the check box deactivates this function. 

Note:  This control is applied to the reclamation of both sunset and R/W media. 

– Age of Last Data Written: The number of days the pool persisted without write access to set a physical stacked volume as a candidate for reclamation. Each physical stacked volume features a timer for this purpose, which is reset when a virtual volume is accessed. The reclamation occurs later, based on an internal schedule. The valid range of possible values is 1 - 365. Clearing the check box deactivates this function. 

Note:  This control is applied to the reclamation of both sunset and R/W media. 

– Days Without Data Inactivation: The number of sequential days that the data ratio of the pool was higher than the Maximum Active Data that was used to set a physical stacked volume as a candidate for reclamation. Each physical stacked volume features a timer for this purpose, which is reset when data inactivation occurs. The reclamation occurs later, based on an internal schedule. The valid range of possible values is 1 - 365. Clearing the check box deactivates this function. If deactivated, this field is not used as a criteria for reclaim. 

Note:  This control is applied to the reclamation of both sunset and R/W media. 

– Maximum Active Data: The ratio of the amount of active data in the entire physical stacked volume capacity. This field is used with Days Without Data Inactivation. The valid range of possible values is 5 - 95(%). This function is disabled if Days Without Data Inactivation is not selected. 

– Reclaim Threshold: The percentage used to determine when to perform reclamation of free storage on a stacked volume. When the amount of active data on a physical stacked volume drops below this percentage, a reclaim operation is performed on the stacked volume. 

Physical volumes hold between the threshold value and 100% of data. For example, if the threshold value is 35% (the default), the percentage of active data on the physical volumes is (100% - 35%)/2 or 15%. Setting the threshold too low results in more physical volumes being needed. Setting the threshold too high might affect the ability of the TS7700 Tape Attach to perform host workload because it is using its resources to perform reclamation. Experiment to find a threshold that matches your needs. 

The valid range of possible values is 0 - 95(%) and can be entered in 1% increments. The default value is 35%. If the system is in a heterogeneous tape drive environment, this threshold is for R/W media. 

