Veritas Volume Manager 4.1 Administrator's Guide (HP-UX 11i v3, February 2007)

Handling Conflicting Configuration Copies in a Disk Group
152 VERITAS Volume Manager Administrator’s Guide
separately on that host. When the disks are subsequently re-imported into the original
shared disk group, the actual serial IDs on the disks do not agree with the expected values
from the configuration copies on other disks in the disk group.
Depending on what happened to the different portions of the split disk group, there are
two possibilities for resolving inconsistencies between the configuration databases:
◆ If the other disks in the disk group were not imported on another host, VxVM resolves
the conflicting values of the serial IDs by using the version of the configuration
database from the disk with the greatest value for the updated ID (shown as
update_tid in the output from the vxdg list diskgroup command). This case is
illustrated below.
Example of a Serial Split Brain Condition that Can Be Resolved Automatically
Disk A
Actual A = 1
Expected A = 1
Expected B = 0
Configuration
Database
Disk B
Actual B = 0
Expected A = 0
Expected B = 0
Configuration
Database
Imported Shared Disk Group
Disk A
Actual A = 1
Expected A = 1
Expected B = 0
Configuration
Database
Disk B
Actual B = 0
Expected A = 1
Expected B = 0
Configuration
Database
Partial Disk Group
Imported on Host X
Disk B Not Imported
1.Disk A is imported on a
separate host. Disk B is not
imported. The actual and
expected serial IDs are
updated only on disk A.
2.The disk group is re-
imported on the cluster. The
configuration copy on disk A
is used to correct the
configuration copy on disk B
as the actual value of the
updated ID on disk A is
greatest.