Problem
Enterprise Vault Exchange Archiving Tasks (2003, 2007, or 2010) may fail due to being unable to contact a Global Catalog (GC) server. Specifying a specific GC server through either the Enterprise Vault Administration Console, or through the "DS Server" registry key will overcome this, but it presents a single point of failure in the Active Directory environment.
Cause
If the specified GC server fails for any reason, the Enterprise Vault archiving tasks cannot find other catalog servers that may be present in the environment.
Solution
Within the DNS Management Console, create multiple Host (A) entries with the same name, each pointing to the IP address of different Global Catalog servers. For example:
GC.domain.com >> 10.10.10.1
GC.domain.com >> 10.10.10.2
Configure Enterprise Vault to use this new Host (A) name as the GC server in the Administration Console (properties of the domain target), or through the "DS Server" registry key.