mt(1)							      General Commands Manual							     mt(1)

NAME

       mt - Magnetic tape manipulating program

SYNOPSIS

       mt [-f tape_device] command [count]

       The mt program gives commands to a magnetic tape drive.

OPTIONS

       This option specifies the tape device to be manipulated.  This option specifies the number of times that the operation is to be repeated.

DESCRIPTION

       If  you	do  not  specify  a  tape  name  with  the  -f	option, the TAPE environment variable is used; if TAPE does not exist, mt uses the
       /dev/ntape/tape0_d0 device.  Note that tape_device must refer to a raw (not block) tape device.	By  default,  mt  performs  the  requested
       operation once.	You can perform operations more than once using the count option.

       The  following  commands  are  available: Backspaces count files.  Backspaces count records.  Writes count End-of-File marks at the current
       position on the tape.  Forward spaces count files.  Forward spaces count records.  This option prepares a SCSI tape for	loading  into  the
       device.	 Not  all  SCSI  tape drives support this command.  Rewinds the tape and places the tape unit offline (count is ignored).  Bring a
       SCSI tape to the ready state if a tape is in the tape path. Currently, this command is only supported in the SCSI/CAM tape driver. Not  all
       SCSI  tape  drives  support this functionality.	Rewinds the tape (count is ignored).  Sets the tape at the specified read position coordi-
       nates. The data obtained when using the rdpos option can be used as an argument to the seek or seekds commands.

	      Use the following options with the rdpos command: The read position short format. This option requires a tape coordinate argument in
	      the following syntax: # mt -f /dev/ntape/tape1 rdpos s

	      READ POSITION short format
		      First block:	3 (0x3)
		      Last block:	0 (0x0)
		      Number of blocks: 0 (0x0)
		      Number of bytes:	0 (0x0)

	      The preceding example provides the following information: The block address associated with the current logical position.  The block
	      address associated with the next block to be transferred from the buffer to the medium.  The number of data  blocks  that  have  not
	      been written to the medium.  The number of data bytes that have not been written to the medium.

	      In  addition  to the information provided by the preceding example, the rdpos s option may display additional messages. Availability
	      of these additional messages depends on the capabilities of the tape drive device.  You will only see such  error  messages  if  the
	      tape device is configured to detect the error state and to display the appropriate message: An error has occurred and the tape posi-
	      tion cannot be returned.	An error has occurred as the device is incapable of reporting block locations.	Number	of  bytes  in  the
	      buffer  field  does not represent the actual number of bytes in the buffer.  Number of blocks in the buffer field does not represent
	      the actual number of blocks in the buffer.  The logical unit is positioned between early-warning and the end of  media  (EOM).   The
	      logical  unit  is at the beginning of media (BOM).  The read position long format. This option requires an argument in the following
	      syntax: # mt -f /dev/ntape/tape1 rdpos l READ POSITION long format
		      File number:  0 (0x0)
		      Block number: 3 (0x3)

	      The following information is returned: The number of file marks between BOM and current logical position.   The  number  of  logical
	      blocks between BOM and the current logical position.

	      In  addition  to the information provided by the preceding example, the rdpos l option may display additional messages. Availability
	      of these additional messages depends on the capabilities of the tape drive device.  You will only see such  error  messages  if  the
	      tape  device  is configured to detect the error state and to display the appropriate message: An error has occurred as the device is
	      incapable of reporting block locations.  File Number and Set Number are unknown The logical unit is positioned between early-warning
	      and  the end of media (EOM).  The logical unit is at the beginning of media (BOM).  The read position short format, with device-spe-
	      cific addresses. This option only works on certain devices and requires a tape coordinate argument as for the s option.

	      The output will be the same format as for the s option, although the device-specific data bytes may differ if  the  device  supports
	      its own format. Not all devices support their own format.  If the d option is not supported by the device, the following	error mes-
	      sage will be displayed: MTIOCRDPOS (dev_specific): I/O error

	      Space to end of recorded data. Currently, this command is only supported in the SCSI/CAM tape driver.  Not all SCSI tape drives sup-
	      port  this functionality.  Positions a tape at the specified coordinates. The output of the rdpos command may be used as an argument
	      to this command. You can specify the value from the First block field when using the s option.  Positions a tape	at  the  specified
	      coordinates. You can use the output from the rdpos command as an argument, and the syntax is as for the seek command.

	      Unlike  the  general  seek  command,  the  seekds command is device-specific. Some tape devices provide a device-specific format for
	      accessing the media position, which differs from the SCSI logical block format defined by the SCSI  standard.   The  device-specific
	      format  may  provide  a  faster way of seeking to a particular position on the tape.  Prints status information about the tape unit.
	      Prepares a SCSI tape for removal from the device.  Not all SCSI tape drives support this functionality.

       Only as many characters as are required to uniquely identify a command need to be specified.

EXIT STATUS

       The mt command returns the following exit status: Success.  Command was unrecognized.  Operation failed.

FILES

       Raw magnetic tape interface with no rewind when closed.	Raw magnetic tape interface with rewind when closed.

SEE ALSO

       Commands:  dd(1)

       Functions:  ioctl(2)

																	     mt(1)