See the topics on
Format the LOGR couple data set and make it available to the sysplex and
When the coupling facility survives the sysplex failurefor additional considerations on LOGR CDS and CF structure
use.
- If you are planning to activate a newly formatted LOGR CDS as
part of the sysplex-wide IPL and this is the first IPL for the sysplex,
then refer to the instructions in Format the LOGR couple data set and make it available to the sysplex.
- If this is not the first IPL for the sysplex, and on the next
sysplex-wide IPL you plan to continue to use a LOGR CDS (or a mirror
copy of one) that had been the last one used for this sysplex, then
ensure the COUPLExx parmlib member specifies the
current LOGR CDS before performing the sysplex-wide IPL or respond
accordingly to message IXC289D during the initial re-IPL. Refer to z/OS MVS System Messages, Vol 10 (IXC-IZP) for
more details.
- If this is not the first IPL for the sysplex, and on the next
sysplex-wide IPL you are planning to activate a newly formatted LOGR
CDS, then IBM® recommends you take additional steps prior
to the sysplex-wide IPL. Cause all applications using the Coupling
Facility structure based log streams to be disconnected and the structures
used by Logger to be unallocated before re-IPLing.
Note: Partitioning
all of the systems for a sysplex-wide IPL can leave the structures
used by Logger still allocated with a FAILED-PERSISTENT connection.
The goal for this case is to avoid having any structures used by Logger
with FAILED-PERSISTENT connections.
A DISPLAY
LOGGER,L command will show which log streams have connections to systems
in the sysplex as well as naming any associated CF structure. The
DISPLAY XCF,STR command will show which structures are allocated within
the sysplex. You can then issue a DISPLAY XCF,STR,STRNAME=structname command for any structure that is still
allocated by Logger. At the bottom of the command response is the
connection status. You can issue SETXCF FORCE,CON,STRNAME=structname,CONNAME=IXGLOGR_xxxx to
force all of the connections and deallocate a structure.
- If this is not the first IPL for the sysplex, and on the next
sysplex-wide IPL you plan to activate a LOGR CDS (or a mirror copy
of one) that had been previously used but this LOGR CDS is not the
last one used for the sysplex, then additional steps prior to the
sysplex-wide IPL are required. Cause all applications using the Coupling
Facility structure based log streams to be disconnected and the structures
used by Logger to be unallocated before re-IPLing (refer to the actions
in the previous bullet).
For this case, if after the sysplex-wide
IPL any structures that Logger would use still have FAILED-PERSISTENT
connections, then unpredictable results may occur. The problems can
result in conflicts between the LOGR CDS state information for log
stream resources and the state information that may also be kept in
the CF structures. When the LOGR CDS log stream state information
indicates there are no outstanding connections to the log stream,
then the CF structure lists are cleared before Logger will allow the
next log stream connection to complete. If the LOGR CDS log stream
state information indicates there were outstanding (failed-persistent)
connections to the log stream, then conflicts could exist between
the LOGR CDS state data and any state data kept in the structure lists.
The conflicting state data can lead to unpredictable results for Logger's
use of the log stream or structure resources. For example, the log
stream may become unusable, loss of data conditions, or log stream
offload errors can result.