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

ShadowImage for z/OS user guide 13
1 ShadowImage for the
XP1024/XP128/XP12000/XP10000
ShadowImage (SI390) is a storage-based hardware solution for duplicating logical volumes that reduces
backup time and provides point-in-time backup. The SI390 source volumes (S-VOLs) contain the original
data and the SI390 target volume(s) (T-VOLs) contain the duplicate data. The user can choose to make up
to three copies of each S-VOL. Because each T-VOL is paired with its S-VOL independently. Each T-VOL can
be maintained as an independent copy set that can be split, resynchronized, and deleted separately from
the other T-VOLs assigned to the same S-VOL.
NOTE: This manual refers to the "z/OS" operating system, however, other operating systems are also
supported. Contact your HP account support representative for a list of supported operating systems.
ShadowImage Components
SI390 operations involve the source and target volumes in the XP1024/XP128/XP12000/XP10000,
Command View XP or XP Remote Web Console, and optionally, the IBM PPRC® host software functions.
The SI390 system components are:
• SI390 volume pairs (S-VOLs and T-VOLs) (see page 13)
• Command View XP or XP Remote Web Console
• (Optional) IBM PPRC host software functions (see page 15)
• (Optional) IBM DFSMSdss host software functions (see page 15)
Figure 1 shows a typical ShadowImage configuration.
Figure 1 ShadowImage for z/OS configuration
Volume Pairs (S-VOLs and T-VOLs)
The XP1024/XP128/XP12000/XP10000 contains and manages both the original and copied SI390
data. SI390 supports a maximum of 8,192 volumes (4,096 pairs: 4,096 S-VOLs and 4,096 T-VOLs).
SI390 performs internal copy operations for logical volume pairs established by the user. Each SI390 pair
consists of one source volume (S-VOL) and up to three target volumes (T-VOLs) that are located in the same
XP1024/XP128/XP12000/XP10000. The SI390 S-VOLs are the source volumes that contain the original