Define virtual volume expiration time

This topic provides instructions to define virtual volume expiration time.

Use the Categories panel on the TS7700 Management Interface to define the virtual volume expiration time. If the Delete Expired Volume Data setting is not used, virtual volumes occupy space on the physical volumes even after they have been returned to scratch. In that case, only when a virtual volume is rewritten is the old data that is released to reduce the amount of active data on the physical volume. With the Delete Expired Volume Data setting, the data that is associated with volumes that have been returned to scratch are deleted after a time period and their old data released.

For example, assume that you have 20 000 virtual volumes in scratch status at any point in time, that the average amount of data on a virtual volume is 400 MB, and that the data compresses at a 2:1 ratio. The space that is occupied by the data on those scratch volumes is 4 000 000 MB or the equivalent of 14 (fourteen) 3592 JA cartridges. By using the Delete Expired Volume Data setting, you could reduce the number of cartridges required in this example by 14.

The parameter Expire Time specifies the amount of time in hours, days, or years.
  • When specifying years the max value is 2000
  • When specifying days the max value is 3650
  • When specifying hours the max value is 87600
The data continues to be managed by the TS7700 after a virtual volume is returned to scratch before the data that is associated with the virtual volume is deleted. A minimum of 1 hour and a maximum of 2000 years can be specified. Specifying a value of "No expiration" means that the data that is associated with the volume is to be managed as it was before the addition of this option. This means that it is never deleted. In essence, specifying a value (other than zero) provides a "grace period" from when the virtual volume is returned to scratch until its associated data is eligible for deletion. A separate Expire Time can be set for each category defined as scratch.