Mtx(1) is a set of low level driver programs to control features of SCSI backup related devices such as autoloaders, tape changers, mediajukeboxes, and tape drives. It can also report much data, including serial numbers, maximum block sizes, and TapeAlert(tm) messages that most modern tape drives implement, as well as do raw SCSI READ and WRITE commands to tape drives. It works like chio(1) but supports more features and drives and runs in users land. There are some amanda (sysutils/amanda-server) scripts, which depend on mtx.