Hitachi ShadowImage for z/OS user guide (December 2005)

ShadowImage for z/OS user guide 37
• SI390 supports multiple T-VOLs for each S-VOL. If you issue a pair status query to an SI390 S-VOL, 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. The SI390 remote console software displays the
LDEV ID and SI390 pair status of all T-VOLs associated with an S-VOL.
• Reverse resync and quick restore operations can be performed on shared SI390/TC390 pairs only
when the TC390 pair is suspended.
Table 10 describes the host pair status reporting for SIz, URz volumes, and SIz/URz shared volumes; and
SI390 volumes, Universal Replicator for z/OS volumes, and ShadowImage and Universal Replicator for
z/OS shared volumes. Table 11 lists the currency of the data on shared SI390/URz volumes based on the
SI390 and URz pair status.
The configuration shown in the following figure is an example of a volume that is functioning as both an
SI390 S-VOL and a TC390 M-VOL. With this configuration, you can:
• Use SI390 to provide on-site backup copies of TC390 M-VOLs.
Table 10 Host pair status reporting for SI390/TC390 shared volumes
Number of SI390
S-VOLs
Number of TC390 Pairs Pair Status Reported by
XP128/XP1024/XP10000/XP12000
00 Simplex
10 SI390 pair status
2 or more 0 SI390 pair status for the pair whose T-VOL has the
lowest LDEV ID
01
TC390
pair status
11
TC390
pair status
2 or more 1
TC390
pair status
Table 11 Currency of a shared SI390 and TC390 volume
SI390 Pair Status TC390 Pair Status
Pending Duplex Suspended
Pending Not current Not current Not current
Duplex Not current Not current CURRENT
SP-Pending Not current Not current CURRENT
V-Split Not current Not current CURRENT
Split CURRENT CURRENT CURRENT
Resync Not current Not current CURRENT
Resync-r - - CURRENT
Suspended Not current Not current Not current