Hitachi TrueCopy for IBM z/OS User and Reference Guide (T5211-96001, June 2007)

A-46 Using PPRC Commands for TrueCopy for z/OS
Hitachi Universal Storage Platform V TrueCopy for IBM z/OS User’s Guide
(3) One (or more) IEA491 and IEA494 messages showing
PAIR SUSPENDED are displayed.
Table A-13 USP V Response Characteristics to Failure Conditions (continued)
Failure Condition TCz Pairs
Suspended?
Expected Messages FREEZE
Function
Failure of NVS on the
RCU;
Failure of RCU read cache
One side of RCU
cache blocked
due to failure
No
(1) The RCU reports IEA480 message (SIM for cache
blocked) to either the MCU or the host processor
(whichever issues the next I/O first). If MCU receives
the SIM, it passes the SIM to the attached host
processor. Therefore, IEA480 is reported when the
next I/O to any device in this MCU issued.
(2) No IEA491 or IEA494 messages are displayed.
Not
activated
One side of RCU
cache blocked
due to
maintenance
No
No IEA480, IEA491, or IEA494 messages are
displayed.
Not
activated
One side of RCU
cache blocked
by SET CACHE
OFF
No
No IEA480, IEA491, or IEA494 messages are
displayed.
Not
activated
Both sides of RCU cache blocked due to
failure
Yes (1) No IEA480(SIM of cache blocked) is displayed.
(2) One (or more) IEA494 messages showing EXTENDED
LONG BUSY are displayed.
(3) One (or more) IEA491 and IEA494 messages showing
PAIR SUSPENDED are displayed.
(4) If CGROUP FREEZE and RUN are issued, IEA494
messages showing PAIR SUSPENDED are displayed when
the MCU accepts CGROUP-RUN. These messages are
from the TCz pairs for which FREEZE option is enabled,
and from main volumes which did not already report
IEA491/IEA494 at (3).
Activated if
the FREEZE
option is
enabled for
the affected
LCU pairs.
Failure of all links between the MCU and
RCU
Yes
(1) IEA480 (SIM for TCz path blocked) message is
reported when the next I/O to any device in this MCU
is issued.
(2) One (or more) IEA494 messages showing EXTENDED
LONG BUSY are displayed.
(3) One (or more) IEA491 and IEA494 messages showing
PAIR SUSPENDED are displayed.
Activated if
the FREEZE
option is
enabled for
the affected
LCU pairs.
Power failure On the MCU No
No IEA480, IEA491, or IEA494 messages are
displayed.
Not
activated
On the RCU Yes
(1) IEA480 (SIM of TCz path blocked) message is
reported when the next I/O to any device in this MCU
is issued.
(2) One (or more) IEA494 messages showing EXTENDED
LONG BUSY are displayed.
(3) One (or more) IEA491 and IEA494 messages showing
PAIR SUSPENDED are displayed.
Activated if
the FREEZE
option is
enabled for
the affected
LCU pairs.
*Note: When one side of the MCU cache is blocked, duplex TCz pairs are not affected, but pending duplex TCz pairs are suspended.
Suspending TCz pairs with pending duplex status provides additional protection in the unlikely event of a cache failure.