Hitachi ShadowImage for z/OS user guide (HIT9503-96004, June 2006)

ShadowImage for z/OS user guide 35
Preparing for ShadowImage Operations
System Requirements
SI390 operations involve the XP1024/XP128/XP12000/XP10000 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. All XP1024/XP128/XP12000/XP10000 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 is ready for SI390 operations, perform the
following tasks:
• SI390 operations affect the I/O performance of the XP1024/XP128/XP12000/XP10000 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 35 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 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 36.
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
0 00 Yes 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
0 11 No -- Yes 0:00
0 12 No -- Yes 0:01
etc. … … … … …