Some embodiments include a cold storage system that processes an input/output (I/O) request. The cold storage system can have a buffer rack and one or more archival storage racks. The buffer rack can be closer to an I/O drive of the cold storage system than the archival storage racks. The cold storage system can operate a fetcher robot to pre-fetch a first data storage medium from the archival storage racks to the buffer rack. The cold storage system can operate a buffer robot to move a second data storage medium from a slot in the buffer rack to the I/O drive. The cold storage system can execute, according to the I/O request, an I/O operation on the second data storage medium at the I/O drive.