HP StorageWorks SAN Virtualization Services Platform Administrator Guide (5697-0934, May 2011)

the DPMs are in an active-passive relationship, meaning that an individual virtual disk is active on
one DPM and on standby on the other DPM within the DPM group. Therefore it is beneficial to
partition your disks between the DPMs.
Virtualization Services Manager
The VSM server has several functions and components. The most visible of these functions is the
VSM user interface. This interface performs functions for the SVSP like HP Command View EVA
performs for EVAs. The VSM application runs on a separate server from HP Command View EVA.
The reason for the custom server configuration is due to other (and less visible) functions performed
by VSM. These other functions include:
• Data import
• Data migration
• Local replication (point-in-time copies, snapshots, and snapclones)
• Asynchronous remote replication
In addition to creating and managing the many objects that exist within the SVSP domain, another
purpose of the VSM user interface is to define the virtualization maps used by the DPM to perform
the virtualization of the I/O. These virtualization maps exist for each SVSP-defined virtual disk,
plus all point-in-time copies, snapshots, snapclones, and remote asynchronous mirrors.
A third function of the VSM software is to move data from one location within the domain to another
location, either within the domain, or in the case of remote mirrors, to another domain. When
going between domains, the VSM software that implements the remote mirror function can use the
built-in iSCSI interface that exists between the two domains.
Administrator tasks
The following sections describe tasks that an administrator performs either routinely, like provisioning
and daily activities such as backups, or infrequently, such as adding or removing arrays, adding
servers, and so on.
Frequently performed tasks
Figure 2 (page 11) illustrates the common functions within VSM that are implemented top-down.
In the figure, four back-end logical units (BELUs) are presented by the various storage arrays to the
SVSP domain. These BELUs are concatenated together to build a pool of blocks (see Pool section).
That storage pool is used to build five virtual disks (see Volume section) that can be presented to
customer servers. In addition, two of these virtual disks are bound together into a consistency group
for presentation to Host Z.
10 SAN Virtualization Services Platform overview