HP StorageWorks XP Remote Web Console Software - Manual (Page 9)

You may operate SIz directly from the host and do not need to use the Remote Web Console
computer, if you use VOS3 DMFVSS, XP for Business Continuity Manager Software™, IBM PPRC
host software functions, or IBM DFSMSdss host software functions.
Volume Pairs and CTGs
ShadowImage for Mainframe performs internal copy operations for logical volume pairs established
by the user. Therefore, you need at least two volumes to use SIz, one for copy source (S-VOL), and
another for copy target (T-VOL). Each SIz pair consists of one S-VOL and up to three T-VOLs, which
are located in the same storage system.
The SIz S-VOLs are the source volumes which contain the original data. The SIz T-VOLs are the
target volumes which contain the backup data. Each T-VOL must be paired with only one S-VOL.
During normal SIz operations, the S-VOLs remain available to all hosts at all times for read and
write I/O operations (except during reverse copy and quick restore operations). When the pair
status is Duplex and if the S-VOL is updated, the differential data between S-VOL and T-VOL will
be copied to the T-VOL regularly. However, since SIz T-VOLs are updated asynchronously, the
S-VOL and T-VOL of the pair in Duplex status may not be identical. Remember that the T-VOLs
become available for host access only after a split operation has been performed.
By using a IBM PPRC command or XP for Business Continuity Manager Software™, you can define
multiple SIz pairs as one CTG. If you define a CTG, you can split all SIz pairs in the group by
using the At-Time Split function. For details about the At-Time Split function, see
(page 12) .
ShadowImage for Mainframe Software
You can operate ShadowImage for Mainframe by using the Remote Web Console computer. The
Remote Web Console computer can be attached to the XP storage systems via the TCP/IP local-area
network (LAN). The Remote Web Console computer communicates and exchanges data directly
with the service processor (SVP) of attached storage systems. You become able to acquire the
information for the structure or status of the storage system, or issue commands to the storage
system.
License
You need to purchase the SIz license and make sure that there is enough licensed capacity according
to the capacity of pairs you are going to create. ShadowImage for Mainframe regards S-VOLs,
T-VOLs, and reserved volumes as the volumes that require the license capacity of SIz, and manage
these volumes. When you purchase a license for volume capacity for use with ShadowImage for
Mainframe, you need to examine how much capacity of volumes you want to use as S-VOLs,
T-VOLs or reserved volumes. The total capacity of volume that you can use cannot exceed the
maximum volume capacity that is licensed to you. You must therefore purchase a license for volume
capacity that is equal to, or more than, the total volume capacity you want to use.
XP for Business Continuity Manager Software
If you issue the XP for Business Continuity Manager Software™ commands to the storage system
from the mainframe hosts, you can create, split, resynchronize, or delete SIz pairs, or you can
display the pair status. For details about the XP for Business Continuity Manager Software™
commands, see
(page 88) .
PPRC Host Software
ShadowImage for Mainframe supports the IBM PPRC host software functions, including TSO PPRC
commands and ICKDSF PPRCOPY commands. SIz pairs can be added, split, resynchronized, and
deleted using these PPRC commands.
(page 90) describes and provides instructions for using PPRC
commands to create and maintain SIz pairs on the XP storage system.
ShadowImage for Mainframe Components 9