HP Storage Provisioning Manager (SPM) Version 2.0 User Guide

G Working with unmanaged arrays
Overview
This section specifies the format of the xml files used to describe the characteristics of unmanaged
storage arrays to SPM 2.0. Unmanaged storage arrays are storage arrays with which SPM cannot
communicate. In order for a user of SPM to track storage allocated within such arrays using SPM,
the characteristics of the arrays are described in xml files which SPM will read.
SPM 2.0 allows users to manage allocation of storage in a number of storage arrays. However,
some users may need to manage types of storage arrays with which SPM cannot communicate
directly. Users can track the allocation of storage in such unmanaged storage arrays within SPM
by creating XML files describing the storage arrays and placing those files in a directory which
SPM examines. SPM reads any files found in the directory and incorporates the information within
them into its model of available storage. Since SPM cannot communicate with unmanaged storage
arrays, users must ensure consistency of the state of the storage arrays and the data about them
within SPM.
Unmanaged storage
SPM 2.0 can communicate with a number of storage arrays as provided by Hewlett Packard. End
users can write adapters to allow SPM to communicate with other storage arrays. If an SPM user
must allocate storage in a storage array for which Hewlett Packard has not provided an interface
and for which no adapter is available, these arrays can be treated as unmanaged arrays within
SPM.
XML file lifecycle
The user must provide SPM with an XML file as described in this document which specifies the
features and configuration of one or more unmanaged arrays. When there are changes to the
state of the unmanaged arrays, the user must modify the XML file representing those in order to
guarantee that the data within SPM is consistent with the state of the array.
XML file location
SPM reads XML files describing unmanaged arrays from a standard location relative to the location
of the application. All files within the specified folder having a file type of “.xml” will be loaded
by SPM. The location examined by SPM is <SPM installation
path>/state/unmanaged_storage/.
XML errors
In the event that an XML file provided to SPM does not follow the specification, an error will be
posted in the SPM log file, and the file will be ignored.
Capacities
All capacities in the following document are in bytes. A pool’s physical capacity is the maximum
capacity that can be provisioned from a pool. A pool’s committed capacity is the part of that pool’s
physical capacity which is allocated to the volumes within the pool. It should be the sum of the
committed capacities of the volumes within the pool, and should be less than the physical capacity.
A pool’s subscribed capacity is the amount of storage promised to volumes within that pool. If a
pool is oversubscribed, its subscribed capacity may be greater than its physical capacity. A pool’s
subscribed capacity will always be greater than or equal to its committed capacity. A volume’s
capacity is the total amount of storage allocated to that volume from the pool that contains it. A
volume’s committed capacity is the amount of that volume’s capacity which is allocated to users.
Unique identifiers
The Unmanaged Array XML files use strings representing two kinds of unique identifiers. All objects
defined within an Unmanaged Array XML file may have an ObjectID. ObjectID identifiers should
78 Working with unmanaged arrays