Question & Answer
Question
Customer requested more detailed clarification of LOGR dataset management in relation to PPRC (or MTMM) configuration, Parmlib ALLOWACCESS parameter, and alternate subchannel usage.
Answer
Applicable to: GDPS/PPRC V3R13 (and higher) and GDPS/MTMM V3R13 (and higher), on z/OS V2R2, with PTFs for APARs OA50775 and OA50781 installed.
How one defines the LOGR CDS (sysplex logger couple dataset) volumes to the Controlling systems depends on whether the LOGR CDS are managed by PPRC remote copy or not; and if managed by PPRC, whether you have specified YES or NO for ALLOWACCESS in IXGCNFxx on the Controlling systems.
The Parmlib IXGCNFxx ALLOWACCESS specification is discussed in the following GDPS publications:
a) Section 2.6 “Preventing Controlling system allocation of the LOGR CDS" ("GDPS/PPRC V3R13 Installation and Customization Guide" ZG24-6703)
b) Section 2.3.1 “Preventing Controlling system allocation of the LOGGER CDS" ("GDPS/MTMM V3R13 Installation and Customization Guide" ZG24-6754)
- If your LOGR CDS are not PPRCed, then define the Site1 and Site2 LOGR CDS and spares as Online at IPL in HCD/IODF to your Controlling systems.
- If you are PPRCing the LOGR CDS and you are not yet running with ALLOWACCESS(NO) in IXGCNFxx, both the Site1 and Site2 LOGR CDS devices must be defined as Online at IPL. Note that this can result in duplicate volume serial (volser) prompts for the LOGR CDS volume pairs under certain circumstances where the secondaries have been failed over unless you have the PPRC secondary devices in MSS1. If the IPL is performed by GDPS, GDPS will reply correctly to the prompts if you have specified PROCOPTS=INTERNAL2 in GEOPLEX OPTIONS. If the IPL is performed outside of GDPS control, you will need to be prepared to reply manually.
- If you are PPRCing the LOGR CDS and you are running with ALLOWACCESS(NO), then you have two options:
- Define the Site1 and Site2 LOGR CDS volumes as Offline at IPL, just as for other PPRCed devices. In this case, when you IPL the Controlling system, WTORs IGGN505A and IXC252D will be issued at IPL time. If you have specified PROCOPTS=INTERNAL2 in GEOPLEX OPTIONS and the load is initiated via GDPS, then GDPS will automatically reply to the IGGN505A. You should use z/OS Auto Reply (PARMLIB AUTOR) capability to automatically reply ‘C’ to the IXC252D in this case as well (and the IGGN505A if not using setting PROCOPTS=INTERNAL2).
- Define the Site1 and Site2 LOGR CDS volumes as Online at IPL. This setup will result in the same duplicate volser prompt issue as we have described above for PPRCed LOGR CDS when not using ALLOWACESS(NO). If your PPRC secondary devices are in MSS1, then the duplicate volser prompts for the LOGR CDS pair cannot occur.
When not using alternate sub-channel set support, the recommended Controlling system setup when the Primary and Alternate LOGR CDS are PPRCed, and excluded from GDPS CDS management is as follows:
- In HCD, define the LOGR CDS volumes as Offline at IPL. This avoids duplicate volser prompts.
- Do not specify LOGR CDS in COUPLExx. This avoids IGGN505A prompt when the Controlling system is IPLed into the sysplex when the Logger is not in use by any systems in the sysplex.
- Specify PROCOPTS=INTERNAL2 in GEOPLEX OPTIONS. This facilitates GDPS to automatically reply to IGGN505A if the Controlling system is IPLed when Logger is already in use by one or more systems in the sysplex.
- Use z/OS Auto Reply to reply ‘C’ to IXC252D.
- Specify ALLOWACCESS(NO) in IXGCNFxx. This avoids XCFAS allocation on the LOGR CDS and eliminates the need to reintroduce the frozen LOGR CDS in a recovery scenario.
When using alternate sub-channel set support, the recommended Controlling system setup when the Primary and Alternate LOGR CDS are PPRCed, on devices in MSS0 and MSS1 and excluded from GDPS CDS management is as follows:
- In HCD, define the LOGR CDS volumes as Online at IPL. This avoids undesirable XCF messages at IPL time.
- Do not specify LOGR CDS in COUPLExx. This avoids IGGN505A prompt when the Controlling system is IPLed into the sysplex when the Logger is not in use by any systems in the sysplex.
- Specify ALLOWACCESS(NO) in IXGCNFxx. This avoids XCFAS allocation on the LOGR CDS and eliminates the need to reintroduce the frozen LOGR CDS in a recovery scenario.
Sample PARMLIB AUTOR to reply to (one or both as needed) of the listed messages:
/* */
/* IGGN505A SPECIFY UNIT FOR dsname ON volser OR CANCEL */
Msgid(IGGN505A) Delay(0S) Reply('CANCEL')
/* */
/* IXC252D REPLY C TO CONTINUE IPL WITHOUT */
/* THE typename FUNCTION, OR R TO RETRY */
/* DATA SET ALLOCATION */
Msgid(IXC252D) Delay(0S) Reply('C')
/* */
Product Synonym
GDPS
Was this topic helpful?
Document Information
Modified date:
08 August 2018
UID
swg21997291