Calculating the snapshot estimated manageable capacity, the numbers of cache management devices, and the subscription limit of the V-VOL capacity

To expand the capacity of a Thin Image root volume, verify that the snapshot estimated manageable capacity is available. Use the following formulas:

Snapshot-estimated-manageable-capacity-for-root-volume-expansion = Snapshot-estimated-manageable-capacity-after-root-volume-expansion - Snapshot-estimated-manageable-capacity-before-root-volume-expansion

Snapshot-estimated-manageable-capacity = (Root-volume-capacity [TB] / 2.6 [TB]) x 3,024 [GB] + (168 [GB] x 2 (consumed-shared-memory [GB]))

Expanding the volumes other than a root volume does not consume the snapshot estimated manageable capacity. You can check the snapshot estimated manageable capacity in the Local Replication window.

To expand the capacity of a Thin Image root volume, verify that the cache management devices are available.

Use the following formula:

number-of-cache-management-devices-for-root-volume-expansion = ceiling ((Root-volume-capacity-after-expansion [TB] / 2.6 [TB])) - ceiling ((Root-volume-capacity-before-expansion [TB] / 2.6 [TB]))

Ensure that the ceiling value enclosed in the parenthesis () is rounded up to the next integer.

Expanding the volumes other than a root volume does not consume the cache management devices.

To expand the capacity of a Thin Image root volume, verify that the capacity after the expansion does not exceed the subscription limit of the V-VOL capacity contained in a DP pool.

Use the following formula:

V-VOL-capacity-added-by-root-volume-expansion = Thin Image-pair-capacity-calculated-based-on- root-volume-capacity-after-expansion - Thin Image-pair-capacity-calculated-based-on-root-volume-capacity-before-expansion

Thin Image-pair-capacity = Σ ceiling ((Root-volume-capacity [MB] × number-of-pairs* × 2  / 42 [MB])) × 42 [MB]+ Σ ceiling ((Root-volume-capacity [MB] × number-of-pairs* × 2 / 2,921,688 [MB])) × 175,434 [MB]

* Use the maximum number of HTI pairs to be created in the applicable snapshot tree as number-of-pairs instead of the number of pairs currently created in the applicable snapshot tree because the allocated pages are not released if you delete some pairs.

Ensure that the ceiling value enclosed in the parenthesis () is rounded up to the next integer.

Expanding the volumes other than a root volume does not add the V-VOL capacity contained in a DP pool in Thin Image.