Hitachi TrueCopy for z/OS (T1711-96009, June 2006)

TrueCopy for z/OS user guide 63
TC390 and SI390 can be used together in the same disk array and on the same volumes to provide
multiple copies of data at the main and/or remote sites. The following table describes the host pair status
reporting for TC390 volumes, SI390 volumes, and TC390/SI390 shared volumes. Table 18 on page 63
shows the currency of the data on a shared TC390/SI390 volume based on TC390 and SI390 pair status.
• For shared TC390/SI390 volumes, the TC390 pair status is reported to the host if you query the R-VOL.
To obtain the SI390 pair status, query the target volume (T-VOL) of the pair.
• SI390 supports multiple target volumes (T-VOLs) for each source volume (S-VOL). If you issue a pair
status query to an SI390 S-VOL (for example, CQUERY), the status for only one SI390 pair is reported
(the pair with the T-VOL with the lowest LDEV ID). To obtain the pair status for the SI390 pair(s) with the
other T-VOL(s), you must direct the host query to the specific T-VOL using the T-VOL’s LDEV ID in the host
command (for example, CQUERY DEVN parameter). SI390 through Command View XP or XP Remote
Web Console displays the LDEV ID and SI390 pair status of all T-VOLs associated with an S-VOL.
The following figures show the various TC390/ShadowImage configurations that share volumes. TC390
supports synchronous and asynchronous operations for shared volumes. The following figure shows an
example of a volume that is functioning as both a TC390 M-VOL and a ShadowImage S-VOL. With this
configuration, you can:
• Use TC390 to provide remote backup copies of SI390 S-VOLs.
• Use SI390 to provide on-site backup copies of TC390 M-VOLs.
Figure 20 TrueCopy and ShadowImage: shared M-VOL/S-VOL
Table 17 Host pair status reporting for TrueCopy/ShadowImage shared volumes
Number of
TC390 Pairs
Number of
SI390 T-VOLs
Pair Status Reported by XP1024/XP128/XP12000/XP10000
00 Simplex
0 1 SI390 pair status
0 2 or more ShadowImage pair status for the pair whose T-VOL has the lowest
LDEV ID
1 0 TC390 pair status
1 1 TC390 pair status
1 2 or more TC390 pair status
Table 18 Data currency of a shared TrueCopy/ShadowImage volume
TC390
Pair Status
ShadowImage Pair Status
Pending
Duplex
Duplex Split-Pending Split Resync Suspended
Pending Duplex Not current Not current Not current CURRENT Not current Not current
Duplex Not current Not current Not current CURRENT Not current Not current
Suspended Not current CURRENT CURRENT CURRENT CURRENT Not current