HP StorageWorks XP Remote Web Console Software - Manual (Page 27)

As for the RAID level, XP Snapshot supports RAID1, RAID5, and RAID6.
XP Snapshot Software Requirements
To use XP Snapshot, all storage system hardware, microcode, and software required for Business Copy
operations must be installed and enabled. You also need to purchase the license key for Business Copy
and install it in Remote Web Console. For detailed information about the license key and software
installation, see the HP StorageWorks XP24000 Remote Web Console User’s Guide.
Note that you must operate the Remote Web Console in modify mode to perform XP Snapshot operations.
Users in view mode can view XP Snapshot information, but they cannot create new pairs or change the
pair status. For information about how to set up and use the Remote Web Console computer, see the
HP StorageWorks XP24000 Remote Web Console User’s Guide.
License Requirements
Capacity used by XP Snapshot will be subtracted from the license capacity for Business Copy. Therefore,
you need to ensure that the license capacity for Business Copy is larger than the capacity to be used by
both Business Copy and XP Snapshot.
Even when a volume is used for multiple purposes, only the capacity of this volume itself is added to
the total volume capacity; there is no need to multiply the capacity of this volume by the number of
purposes it is used for. For example, even if you share one volume as XP Snapshot P-VOL and Business
Copy P-VOL, only the capacity of the volume itself is added to the total volume capacity and there is
no need for it to be doubled.
Shared Memory Requirements
The shared memory for the differential table and the V-VOL management area must be installed on the
base board. Note that you cannot share the memory for the V-VOL management area with the memory
of XP Thin Provisioning.
Requirements for RAID Manager
To use RAID Manager for XP Snapshot operations, you need to have one volume for RAID Manager’s
command device. For details about how to set the command device, see the HP StorageWorks XP
RAID Manager User’s Guide.
Operational Requirements
This section explains the information you need to know when you perform XP Snapshot operations.
Calculating the Maximum Number of Pairs
The number of XP Snapshot pairs that can be created for a subsystem depends on the number of
differential tables, the capacity of shared memory for the V-VOL management area, or the number of
pair tables. Calculate the number of XP Snapshot pairs that can be created, first by using the number of
differential tables, then by using the capacity of shared memory for the V-VOL management area, and
finally by using the number of pair tables. Compare the three calculation results. The smallest value is
the maximum number of XP Snapshot pairs that can be created for the subsystem. However, note that
you may be able to create fewer XP Snapshot pairs than the calculation results when there are volumes
for XP Thin Provisioning in the same subsystem.
The following are the descriptions of the calculation of the number of XP Snapshot pairs that can
be created based on the number of differential tables, the capacity of shared memory for the V-VOL
management area, or the number of pair tables.
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