PJ40711: DASD SSID CHANGE CAUSED A DEVICE TO BE CROSS-LINKED ON TWO SSST CHAINS RESULTING IN A LOOPING ECB AND SYSTEM HANG.
Closed as program error.
See Problem Summary.
PAR NUMBER: PJ40711 PRODUCT: z/TPF FUNCTIONAL AREA: RECORD CACHE SUBSYSTEM SHIPPED IN PUT: 10 ABSTRACT: A DASD subsystem ID (SSID) changed during a VM Hyperswap causing a device to be cross-linked on two subsystem status table (SSST) chains. This resulted in a CYEA CTL-10 and system hang. PACKAGE CONTENTS: Source Segments: (C) base/rt/css2.asm (C) base/macro/cz1se.mac Object Only Binaries: None. Configuration Independent Binaries: (C) base/load/CSS2.so (C) base/obj/css2.o Support Files: base/lst/CSS2.map base/lst/css2.lst OTHER BINARIES TO BUILD: YES (C) os390/bin/amx1.pds (C) os390/bin/ppcp.pds (C) os390/bin/stc.pds (C) os390/obj/amx1.o (C) os390/obj/ccmcdc.o (C) os390/obj/dgr0.o (C) os390/obj/sdmu.o (C) os390/obj/stcc.o (C) os390/obj/stci.o (C) os390/obj/stcl.o (C) os390/obj/stpp.o COMMENTS: When a VM Hyperswap occurred and switched DASD controllers, a state-change-pending interrupt was presented triggering TPF to query status. The query returned a different SSID than was detected at IPL time when the reporting device was mounted. Since the new SSID was not found in the SSST, TPF created a new entry and chained the reporting device to it, assuming it was a new device entering the configuration for the first time. Since the device was already mounted, this action caused it to be cross-linked on two SSST chains. A CTL-10 in CYEA occurred followed by a system hang, since it was unable to react to subsequent state change interrupts. A manual IPL was required.
SOLUTION: CSS2.ASM has been modified to check if a device is already mounted on another SSST chain, when the SSID reported following a state-change is not found in the SSST. If it is already mounted, the old SSID and existing SSST slot will be reused to avoid cross-linking problems. CSS2.ASM will issue a SNAPC dump to capture diagnostic data. An IPL is recommended, at the earliest convenience, to rebuild the SSST with the current SSIDs. COREQS: NO None. MIGRATION CONSIDERATIONS: YES Functional, automation, and operation changes: A new snapc dump, 001245, has been created to report an SSID mismatch. BUILD COMMANDS AND INSTRUCTIONS: YES #maketpf commands for linux maketpf -f CSS2 css2.o maketpf CSS2 link #maketpf commands for z/OS maketpf -f amx1 amx1.o maketpf -f ppcp ccmcdc.o stpp.o maketpf -f stc dgr0.o sdmu.o stcc.o stci.o stcl.o maketpf amx1 link maketpf ppcp link maketpf stc link UPDATED INFORMATION UNITS: YES z/TPF Messages (System Error, Offline, and Program Status Word) See your IBM representative if you need additional information. DOWNLOAD INSTRUCTIONS: http://www.ibm.com/software/htp/tpf/maint/maintztpf.html APAR URL: http://www.ibm.com/software/htp/tpf/ztpfmaint/put10/PJ40711.htm
Reported component name
Reported component ID
NoSpecatt / Xsystem
Last modified date
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
Fixed component name
Fixed component ID
Applicable component levels
R110 PSY UP