The import function requires that OAM is active, that the library for the import operation is online and operational, and that the cartridge entry installation exit (CBRUXENT) is not disabled. This environment is necessary for the imported logical volumes to go through entry processing. An import operation is more restrictive than an export operation in that only one import operation is allowed per physical library, while one export operation is allowed per logical library (VTS). Also, import and export operations are not allowed to execute simultaneously in the same library (VTS).