In order for Worker drive mapping to occur, the auto_mount flag must be set in the Worker configuration. In order for the client drive maps to be attached to the job at submission time, the auto_mount flag must also be set as a job flag. Additional maps can be set in the client_drive_map configuration.
There are a number of issues involved, mostly having to do with authentication. Additionally, there have been cases where the drive maps are already set, and they conflict with the Worker's attempt to map the drive. Windows 2000 can't handle two different maps with the same drive letter.
Drive letter mapping is incompatible with Unix, so dirmap will need to be used in a cross-platform Maya render pipeline. However, it won't work for any other application. In other cases, UNC will have to suffice.
