Understanding IBM Enterprise Storage Capacity Calculations

Capacity values for IBM arrays may appear different from what is reported by the IBM CLI or IBM Tools, as IBM uses a decimal gigabyte--10^9 bytes, while IT Analytics uses 1024 for a KB when converting to GB.
For FB open systems hosts, an extent is 1 GB. For CKD IBM zSeries or S/390 systems, an extent is 1 cylinder (.92 GB).

In the Scope Selector, you can narrow the report output by selecting values for the following criteria:

Table: Understanding IBM Enterprise Storage Capacity Calculations

Column name	Description
Array Site	The Array Site ID.
Storage Array	The physical storage system; Drill down to the IBM Array Detail.
DA Pair	Device adapter pair number--the physical I/O enclosure location. If the DA Pair is an even number, it indicates the first DA pair in the enclosure; an odd number indicates the second DA pair in the enclosure.
Capacity	The capacity of all disks belonging to the Array Site.
# of Disks	Number of disks associated with this Array Site. See IBM Disk Summary .
Array Name	Links to the IBM Array Summary. See IBM Array Summary .
Disk RPM	The disk revolutions per minute, such as 10000 or 15000.
State	assigned, unassigned, unavailable, initializing. Indicates if the array site is assigned to the array. If the state is unavailable, its capacity is not included in the total array capacity calculation, as shown in the Array Capacity and Utilization report.
Disk Class	Enterprise fibre channel drives (ENT) or Nearline ATA drives (NL).