We're looking to implement MediaAgent replication between a remote site and our datacenter.  While trying to configure the replication, it appears like I can't use our existing MagLib at the datacenter location for the replication destination.  Is this true?  Do the MagLibs used for MediaAgent replication need to be configured for replication prior to being used for any other type of backup data storage?

Media Agent (and other types of replication whether done within or outside of CV) require a special type of library to be configured.

This needs to be done before you can set the replication up to use the library.

http://documentation.commvault.com/commvault/release_8_0_0/books_online_1/english_us/features/remote_office/remote_office.htm

Pre-Requisites

The MediaAgent Replication solution replicates data from one MediaAgent to another; typically, this would involve a MediaAgent installed in a remote office, and one installed at a centralized data center, although several remote office MediaAgents can replicate their data to the same centralized MediaAgent. Note that each remote MediaAgent will require a different mount path on the centralized MediaAgent.

Each MediaAgent computer requires the following:

-Shared Magnetic Library configured to use replicated disks on both source (remote office) and destination (centralized data center) MediaAgents; see Overview of Magnetic Libraries on Replicated Disks. http://documentation.commvault.com/commvault/release_8_0_0/books_online_1/english_us/features/magnetic_library/magnetic_library.htm#Overview_of_Magnetic_Libraries_on_Replicated_Disks