If an administrative VOB becomes unavailable

When an administrative VOB or PVOB is unavailable, all other VOBs in its administrative hierarchy are affected.

Many operations on global types and their local copies require access to the administrative VOB and will fail if that access cannot be obtained. For example:

Attempts to lock a VOB that has an AdminVOB hyperlink to an unavailable VOB fail.
Attempts at other VOBs in the hierarchy to create instances of a global type defined in an unavailable VOB produce the following error:
cleartool: Error: Unable to access administrative VOB AdminVOB-tag of VOB-tag
The output of cleartool describe for a VOB that has an AdminVOB hyperlink to an unavailable VOB may not show the hyperlink.

Note: An administrative VOB does not have to be mounted to be available for these operations, but it must be registered and must have a tag in the region from which the operation is attempted.

An administrative VOB (like any VOB) can become unavailable for a number of reasons, including the following:

The VOB server host is down or disconnected from the network.
Rational® ClearCase® has been stopped on the VOB server host.
The VOB is replicated but has no replica in the current registry (see Replicated administrative VOB hierarchies).
The VOB is being reformatted. When reformatting one or more members of an administrative VOB hierarchy, start at the bottom of the hierarchy and work your way up so that no member of the hierarchy is accessible while its administrative VOB is not.