Veritas Volume Manager 5.0 Troubleshooting Guide Guide (September 2006)

94 Error messages
Understanding messages
V-5-1-5161
VxVM vxplex ERROR V-5-1-5161 Plex plex not attached.
■ Description: An attempt was made to snap back a detached plex.
■ Action: Reattach the snapshot plex to the snapshot volume.
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.