Veritas Volume Manager 5.0 Troubleshooting Guide, HP-UX 11i v3, First Edition, May 2008

97Error messages
Understanding messages
V-5-1-5162
VxVM vxplex ERROR V-5-1-5162 Plexes do not belong to the same
snapshot volume.
■ Description: An attempt was made to snap back plexes that belong to
different snapshot volumes.
■ Action: Specify the plexes in separate invocations of vxplex snapback.
V-5-1-5929
VxVM vxconfigd NOTICE V-5-1-5929 Unable to resolve duplicate diskid.
■ Description: VxVM has detected disks with duplicate disk identifiers. Arrays
with mirroring capability in hardware are particularly susceptible to such
data corruption, but other causes are possible as explained below.
In releases prior to 3.5, VxVM selected the first disk that it found if the
selection process failed. From release 3.5, the default behavior of VxVM was
to avoid the selection of the wrong disk as this could lead to data corruption.
If VxVM could not determine which disk was the original, it would not
import the disks until they were reinitialized with a new disk ID.
From release 5.0, VxVM checks the unique disk identifier (UDID) value that
is known to the Device Discovery Layer (DDL) against the UDID value that is
set in the disk’s private region. The udid_mismatch flag is set on the disk
if the values differ. If set, this flag is displayed in the output from the
vxdisk list command.
A new set of vxdisk and vxdg operations are provided to handle such disks;
either by either writing the DDL value of the UDID to a disk’s private region,
or by tagging a disk and specifying that it is a cloned disk to the
vxdg import
operation.
■ Action: User intervention is required in the following cases:
■ Case 1: Some arrays such as EMC and HDS provide mirroring in
hardware. When a LUN pair is split, depending on how the process is
performed, this can result in two disks that have the same disk
identifier and UDID value. See ‘‘Handling Disks with Duplicated
Identifiers’’ in the ‘‘Creating and Administering Disk Groups’’ chapter
of the Veritas Volume Manager Administrator’s Guide for full details of
how to deal with this condition.
■ Case 2: If disks have been duplicated by using the dd command or any
similar copying utility, you can use the following command to update
the UDID for one or more disks:
# vxdisk [-f] updateudid disk ...
This command uses the current value of the UDID that is stored in the
Device Discovery Layer (DDL) database to correct the value in the