HP XP P9000 Continuous Access Synchronous for Mainframe Systems User Guide

DescriptionVolume
applies to
Suspend type
PPRCBCMRWC
The main system detected an error condition at the remote
system (RCU), that caused the main system to suspend the
pair. The S-VOL suspend type is S-VOL Failure by MCU.
P-VOL
S-VOL
SUSPEND(06)SUSPCU(06)by RCU
The main system detected that the S-VOL status changed
to Simplex because the user released the pair from the
P-VOLSUSPEND(07)SUSPER(07)Delete pair
to RCU
remote system. The pair cannot be resynchronized
because the S-VOL does not have the Suspend status.
The main system detected an error during communication
with the remote system, or an error during update copy.
P-VOL
S-VOL
SUSPEND(08)SUSPCU(08)S-VOL
failure
In this case, the S-VOL suspend type is usually S-VOL
Failure. This suspend type is also used when the number
of paths falls below the minimum number of paths setting
on the RCU Option dialog box.
The main system could not find valid control information
in its nonvolatile memory during IMPL. This condition
P-VOL
S-VOL
SUSPEND(09)SUSPER(09)MCU IMPL
occurs only if the main system is without power for more
than 48 hours (that is, power failure and fully discharged
backup batteries).
The pair was suspended by the CGROUP/FREEZE TSO
command.
P-VOL
S-VOL
SUSPEND(0A)SUSPOP(0A)by FREEZE
The pair was suspended before the initial copy operation
was complete. The data on the S-VOL is not identical to
the data on the P-VOL.
P-VOL
S-VOL
SUSPEND(08)SUSPER(50)Initial copy
failed
System behavior
Note the following behaviors for suspended pairs:
• The main system stops performing update operations to the S-VOL. It may or may not continue
accepting write I/Os to the P-VOL depending on the P-VOL fence level setting and suspend
option.
• If an update fails, the main system maintains exact synchronization by reporting a unit check
and de-committing the P-VOL update. This ensures that both the host system and application
program regard the write operation to the P-VOL as failed.
• If the main system accepts subsequent write I/Os for a suspended P-VOL, the system records
the updated data in the P-VOL tracks as differential data. When a suspended pair is
resynchronized, the main system copies the out of sync P-VOL tracks to the S-VOL as differential
data.
• Cnt Ac-S Z does not allow access to an S-VOL while the pair is suspended (when mode20=ON,
Read access is accepted).
• When a pair is suspended, whether user requested or due to failure, the main system generates
sense information to notify the hosts. If the host system supports IBM PPRC (and the “PPRC
support by host” CU option is enabled), this notification results in an IEA494I and/or IEA491E
system console message, which indicates the reason for suspension.
Monitoring copy operations, I/O statistics
You can monitor copy operations data and I/O statistics in the Usage Monitor window. This topic
shows you how to do this, and also how to perform the following tasks:
• “Selecting data for the usage monitor graph” (page 79)
• “Resizing the usage monitor graph, saving data” (page 80)
78 Monitoring and maintenance