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

20 TrueCopy for the XP1024/XP128/XP12000/XP10000
NOTE: This mode information was current at the time of publication of this document, but it may change.
Contact your HP account support representative for the latest XP1024/XP128/XP12000/XP10000 SVP
mode information.
XP1024/XP128/XP12000/XP10000 performing TC390A operations (main and remote) use sidefiles in
cache for storing the TC390A recordsets. HXRC also uses cache sidefiles. Disk arrays performing TC390A
and/or HXRC must have sufficient cache installed to handle the increased sidefile usage. Insufficient cache
can degrade disk array I/O performance and cause command retry requests and state-change-pending
(SCP) messages. For more information on cache usage and sidefile thresholds, see
”Inflow Control of
Recordsets” on page 32
.
Table 4 XP1024/XP128/XP12000/XP10000 modes for TrueCopy for z/OS
Mode Description
20 Enables TC390 – R-VOL read-only function (RCU only).
21 Required ON for MCUs and RCUs that connect to channel extenders.
36 TC390 Synchronous – Selects function of CRIT=Y(ALL) or CRIT=Y(PATHS).
Mode 36 ON: CRIT=Y(ALL) => equivalent to Fence Level = Data.
Mode 36 OFF: CRIT=Y(PATHS) => equivalent to Fence Level = Status.
38 TC390 – Changes SSB reported against the WRITE I/O to the M-VOL in critical state.
Mode 38 ON: Intervention required.
Mode 38 OFF: Command rejected (PPRC specification).
45 HXRC – Sleep Wait suppressing option (see modes 61, 85, 86, 97; see ”HXRC Device Blocking and
Load Balancing” on page 212). When Mode 45 is ON and Mode 61 is ON, WRITE I/Os for LDEVs
are blocked by the threshold specified by SDM.
Mode 45 OFF: Sidefile threshold activates Sleep Wait timer at the sleep wait threshold.
Mode 45 ON: Sidefile threshold does not activate Sleep Wait timer at the sleep wait threshold.
61 HXRC – Enables the DONOTBLOCK option of the XADDPAIR command (see mode 45; see ”HXRC
Device Blocking and Load Balancing” on page 212).
Must be OFF if the operating system does not support the DONOTBLOCK option.
Mode 61 OFF: DONOTBLOCK option ignored.
Mode 61 ON: DONOTBLOCK option activated.
64 TC390 CGROUP – Defines scope of CGROUP command within the
XP1024/XP128/XP12000/XP10000. Must be OFF for GDPS.
Mode 64 OFF: TC390 volumes behind the specified LCU pair (main and remote LCUs).
Mode 64 ON: All TC390 volumes in this XP1024/XP128/XP12000/XP10000.
85, 86 HXRC – Variable sidefile threshold (see modes 45, 97, 98; see ”HXRC Device Blocking and Load
Balancing” on page 212).
Mode 85 ON and Mode 86 OFF: Thresholds for Sleep wait/SCP/Puncture = 30/40/50%
Modes 85 and 86 OFF: Thresholds for Sleep wait/SCP/Puncture = 40/50/60%
Mode 85 OFF and Mode 86 ON: Thresholds for Sleep wait/SCP/Puncture = 50/60/70%
Modes 85 and 86 ON: Thresholds for Sleep wait/SCP/Puncture = 60/70/80%