Hitachi ShadowImage for z/OS user guide (HIT9503-96007, October 2007)

38 ShadowImage for the XP1024/XP128/XP12000/XP10000/SVS 200
Preparing for ShadowImage Operations
System Requirements
SI390 operations involve the XP1024/XP128/XP12000/XP10000/SVS 200 containing the S-VOLs and
T-VOLs, the SI390 feature enabled on the Command View management station or XP Remote Web
Console, and (optional) S/390 host PPRC software functions. The SI390 system requirements are:
• XP1024/XP128/XP12000/XP10000/SVS 200. All XP1024/XP128/XP12000/XP10000/SVS 200
hardware, microcode, and software required for SI390 operations must be installed and enabled.
• Command View management station (user-supplied Windows®-based PC) or XP Remote Web Console.
NOTE: You must operate the Command View management station or XP Remote Web Console in
Modify mode to perform SI390 operations. Users in view mode can only view SI390 information.
• SI390 feature license key installed.
Preparing for ShadowImage Operations
To ensure that the XP1024/XP128/XP12000/XP10000/SVS 200 is ready for SI390 operations, perform
the following tasks:
• SI390 operations affect the I/O performance of the XP1024/XP128/XP12000/XP10000/SVS 200
because of the additional write operations to the T-VOLs. If you have not already done so, you should
consider the relative importance of the disk array’s I/O performance and the backup SI390 copies. For
example, assigning three T-VOLs to each S-VOL takes more resources than assigning only one or two.
You can also use the SI390 copy pace option to reduce the impact of the SI390 initial copy operations.
Using a slower copy pace minimizes the impact of zSeries and SI390 operations on I/O performance,
while a faster copy pace produces point-in-time copies more quickly but may affect I/O performance.
The SI390 initial copy operation is performed only once to each T-VOL (unless the pair is suspended).
• Identify the volumes (LDEVs) that will be the SI390 volumes. For each volume, write down the CU image
and LDEV ID, whether the volume will be an S-VOL or T-VOL, and the other volume(s) in its pair (see
Table 9 on page 38 for a sample table). The S-VOLs will remain fully accessible to all hosts throughout
normal SI390 operations (except during reverse resync and quick restore). The T-VOLs will need to be
varied offline before being reserved for SI390 operations. After assigned to a pair, a T-VOL rejects all
write I/Os, except when the pair is split.
• SI390 and TC390 can function together in the same XP1024/XP128/XP12000/XP10000/SVS 200 to
provide both internal and remote backup for your important data. If you are planning to combine
SI390 and TC390, read the important configuration information in ”Combining ShadowImage and
TrueCopy Operations” on page 39.
Combining ShadowImage with Other Data Management Operations
SI390 supports concurrent operations with the following data management functions:
Table 9 Sample table for ShadowImage configuration information
CU # LDEV S-VOL? Associated T-VOL(s) T-VOL? Associated S-VOL
000Yes 0:10, 0:11 No --
0 01 Yes 0:12, 0:13 No --
etc. … … … … …
0 0F Yes 0:2E, 0:2F No --
0 10 No -- Yes 0:00
011 No -- Yes 0:00
012No -- Yes 0:01
etc. … … … … …