HP Application Recovery Manager software A.06.10 Installation and licensing guide (March 2008)

When a capacity based license is being checked, the amount of total disk space on
logical units that have been backed up is compared to the capacity of licenses
installed.
License checking is done in such a way as not to prevent you from performing instant
recovery or a backup even if you have run out of licensed capacity. In these
circumstances a warning message appears during the backup session informing you
that you have exceeded your licensed capacity.
Capacity of used disks is calculated based on historical information gathered during
each ZDB backup session. The time interval taken into account is twenty-four hours.
Application Recovery Manager calculates used disk capacity based on the disks that
were used in all sessions in the last twenty-four hours and compares the calculated
capacity with the licensed capacity.
If a license violation occurs, a warning message is issued during the backup. In
addition, the license reporting tool is run daily and writes a notification to the
Application Recovery Manager Event Log if the licensed capacity is exceeded.
Used capacity calculation
The used capacity calculation calculates the licensed capacity of each disk array
type used in the past twenty-four hours. Disks used two or more times in the specified
time interval are only counted once. Disk array units are identified by their
identification numbers taken from each array. The use of array identification numbers
means that it is possible to know when an array has already been counted.
If a ZDB backup has been run, the original unit’s total capacity is calculated both for
ZDB used capacity per disk array, and in addition, that used for instant recovery
capacity per disk array.
For example, imagine a scenario where there are two disk arrays. On one array
there is a single disk (App. 1) with a capacity of 200 GB being used for data
protection. Backup sessions are triggered three times a day. Three replicas at a time
are kept, these are rotated for instant recovery purposes. On the second disk array
there are two disks (App. 2 and App. 3) with capacities of 150 GB and 120GB
respectively. Backup is run once a day on App.2 disk. On App. 3, backup is run
three times a day and five different replicas are rotated for instant recovery. See
Figure 40 on page 136.
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