– 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. – 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. – 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. – 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. Chapter 9. Configuring and operating the IBM TS7700  433 Note:  This control is applied to the reclamation of both sunset and R/W media. Note:  This control is applied to the reclamation of both sunset and R/W media. Note:  This control is applied to the reclamation of both sunset and R/W media. Draft Document for Review February 7, 2020 3:15 pm 8464ch09_Oper.fm