Error Message

kernel: sd 2:0:0:14: reservation conflict
kernel: VxVM vxdmp V-5-0-112 disabled path 66/0x0 belonging to the dmpnode 201/0xd0 due to path failure

RHEL5U8 kernel SCSI layer error handling routine introduced a new error type:

DID_NEXUS_FAILURE

This new error type is not handled well by VxDMP, resulting in dmp paths getting disabled during SCSI3 PGR operations.

A supported hotfix has been made available for this issue. Please contact Veritas Technical Support to obtain this fix. 

If there are plans to upgrade to RHEL5U8 or are currently running RHEL5U8 kernel 2.6.18-308.el5 or later kernels and are running VxVM 5.1 and later. Veritas recommends installing VxVM5.1SP1RP2P3HF5

If there are plans to upgrade to RHEL5U8 or are currently running RHEL5U8 kernel 2.6.18-308.el5 or later kernels and are running VxVM 6.0 or 6.0RP1. Veritas recommends installing VxVM6.0RP1HF1

The workaround available are:

a) Downgrade the kernel to pre RHEL5U8.
b) Configure vxfenmode in disabled mode.

 

 

SCSI3 PGR (Persistent Group Registrations) operations on a VxDMP (VERITAS Dynamic Multi-Pathing) dmpnode result in VxDMP path disablement. This also can cause:
• Reservation conflict immediately followed by VxDMP error V-5-0-112, whenever SCSI3 PGR operations are executed on a dmpnode. • When a node is rebooted, the surviving node(s) may see diskgroups go into dgdisabled state and file system(s) get disabled. If VCS is managing resources, then resource faults are observed. This occurs because dmp paths and dmpnodes are being disabled as a result of multiple SCSI3 PGR operations. • When a node is rebooted. The surviving node(s) may panic. The panic will be initiated by VxFEN as it is trying to avoid a split brain condition. This occurs because dmp paths and dmpnodes are disabled as a result of multiple SCSI3 PGR operations, then re-enabled by the VxDMP recovery daemon.

ETrack: 2866527