System Panics To Prevent Potential Data Corruption - Symantec XGS-4728F Installation Manual

System panics to prevent potential data corruption

When a system has a split brain condition and is ejected from the VCS One
cluster, it panics and displays the following console message:
How vxfen driver checks for a pre-existing split brain
condition
The vxfen driver prevents an ejected system from rejoining the VCS One
cluster after the private network links fail and before they are repaired.
For example, suppose that system 1 and system 2 are part of a VCS One cluster
that functions normally when the private network links are broken. Also
suppose system 1 is the ejected system. When system 1 reboots before the
private network links are restored, its membership configuration does not show
system 2; however, when it tries to register with the coordinator disks, it
discovers system 2 is registered with them. Given this conflicting information
about system 2, system 1 does not join the VCS One cluster and returns an error
from vxfenconfig. The message is similar to the following:
vxfenconfig: ERROR: There exists the potential for a preexisting
split-brain. The coordinator disks list no nodes which are in the
current membership. However, they also list nodes which are not in
the current membership.
I/O Fencing Disabled!
The following information also appears:
However, the same error can occur when the private network links are working
and both systems go down, system 1 reboots, and system 2 fails to come back up.
From the view of the VCS One cluster from system 1, system 2 may still be
registered on the coordinator disks.
VXFEN:vxfen_plat_panic: Local cluster node ejected from cluster
to prevent potential data corruption.
<date> <system name> vxfen: WARNING: Potentially a preexisting
<date> <system name> split-brain.
<date> <system name> Dropping out of cluster.
<date> <system name> Refer to user documentation for steps
<date> <system name> required to clear preexisting split-brain.
<date> <system name>
<date> <system name> I/O Fencing DISABLED!
<date> <system name>
<date> <system name> gab: GAB:20032: Port b closed
Troubleshooting
Troubleshooting I/O fencing
153