Pool Subscription Limit - HP XP7 User Manual

Note that in this scenario, if the actual pool usage percentage is 50.1%, only 50% appears on
the Remote Web Console window because the capacity amount is truncated after the decimal
point. If the threshold is set to 50%, a SIM and an SNMP trap are reported even though the pool
usage percentage appearing on the screen does not indicate an exceeded threshold.

Pool subscription limit

The value of using subscription limit is to manage the maximum amount of over-provisioning that
is acceptable for a pool. By managing the pool subscription limit, you can control the potential
demand for storing data that might exceed the pool capacity.
The subscription limit is the ratio (%) of the total THP V-VOL capacity that has been configured to
the total capacity of the pool. When the subscription limit is set, you cannot configure another THP
V-VOL if the new THP V-VOL capacity would cause the subscription limit to be exceeded.
For example, if the pool capacity is 100 GB and the subscription limit is 150%, you can configure
up to a total of 150 GB of capacity to the THP V-VOLs related to the pool.
The following figure depicts setting the subscription limit of pool capacity.
Monitoring total THP V-VOL subscription for a pool
You can configure the Subscription Limit of total THP V-VOL capacity to pool capacity. This prevents
a new THP V-VOL capacity that exceeds the configured subscription limit from being allocated and
is associated with the pool. If you specify more than 100% as the Subscription Limit or the
subscription limit is not set, you must monitor the free capacity of the pool because it is possible
that writes to the THP V-VOLs may exceed pool capacity.
The used value displayed on the cell for Current in the Subscription (%) is truncated after the decimal
point of the calculated value. Therefore, the actual percentage of THP V-VOL assigned to the pool
may be larger than the value displayed on the window. If you create a new THP V-VOL of the
same size as the existing THP V-VOL, the larger size of capacity which is displayed on the Current
cell is necessary.
136 Configuring thin provisioning