V-VOL page reservation requirement

The V-VOL full allocation is performed in a range less than the depletion threshold size of the pool. If the capacity of V-VOLs is larger than the depletion threshold size, the full allocation operation is rejected.

CautionThe page reservation function is not supported by the following pools. To prevent data writing from being disabled due to pool overflow, you must monitor the free area of these pools frequently.
  • Pools that contain pool volumes belonging to a parity group with accelerated compression enabled
  • Pools with capacity saving enabled

Use the following formula to calculate the reserved page capacity for each pool. In the formula, the value enclosed in ceiling( ) must be rounded up to the nearest whole number.

Reserved capacity for each pool [block] =
ceiling(CV-capacity-of-V-VOL [block] / 86016) * 86016 + ceiling(CV-capacity-of-V-VOL [block] /
6442082304) * 4 * 86016 - used-capacity-of-V-VOL [block]