tape(C)


tape -- magnetic tape maintenance program

Syntax

tape [ -8cfis ] [ -a arg ] command [ device ]

Description

The tape command sends commands to, and receives status from, the tape subsystem. tape can communicate with QIC-02 cartridge, SCSI (including HP DAT) tape drives, and QIC-40, QIC-80, and Irwin mini-cartridge tape drives. (The Irwin specific program mcart(C) is invoked automatically by tape when options specific to the Irwin driver are used.)

The tape command reads /etc/default/tape to find the default device name for sending commands and receiving status. For example, the following line in /etc/default/tape will cause tape to communicate with the QIC-02 cartridge tape device:

   device = /dev/xct0
If a device name is specified on the command line, it overrides the default device. tape queries the device to determine its device type. If the device does not respond to the query, tape will print a warning message and assume the device is a QIC-02 cartridge tape. The tape drive type may be specified using the following flags:

-8
QIC-80 mini-cartridge tape

-c
QIC-02 cartridge tape

-f
QIC-40 mini-cartridge tape

-i
Irwin mini-cartridge tape

-s
SCSI tape (including HP DAT)
See the tape(HW) manual page and the Getting Started Guide for a list of supported tape drives.

Commands

The following commands can be used with the various tape drivers supported under UNIX. The letters following each command indicate which drivers support the command:

A
All drivers

C
QIC-02 cartridge tape driver (obsolete)

F
QIC-40 and QIC-80 mini-cartridge tape drivers (obsolete)

I
Irwin mini-cartridge tape driver (obsolete)

S
SCSI tape driver (including HP DAT)

Note that the commands marked only with C, F, and I were provided in previous releases, but are no longer supported.

The amount and reset commands can be used while the tape is busy with other operations. All other commands (including status) wait until the currently executing command has been completed before proceeding.

When you are using the non-rewinding tape device or the tape commands rfm and wfm, the tape drive light remains on after the command has been completed. Use the command tape rewind to clear this condition.

The -a option allows an argument arg to be passed to the commands: format, partition, rfm, rsm, setcomp, setblk, setpart, wfm, and wsm.


amount (C,S,F)
Report amount of data (kilobytes) in current or last transfer. The counter resets after 4 GB (4194304 kilobytes), so this must be taken into account for transfers larger than this limit.

drive (I) (obsolete)
Display information about the Irwin driver and the tape drive. See the mcart(C) manual page for more details.

eod (S)
Position the tape to the EOD, the end of written data. See the dat(HW) manual page for more information.

erase (C,S,F)
Erase and retension the tape cartridge.

format (F,I) (obsolete)
Format the tape cartridge. Floppy controller-based tapes must be formatted before they can be used. This command takes approximately one minute per megabyte of tape capacity. For QIC-40 and QIC-80 tape drives only, the argument to the -a flag can be used to specify the number of tracks to be formatted. Only even numbers less than or equal to the number of tracks on the tape are allowed. See the tape(HW) manual page for more information. If no argument is given, the entire tape will be formatted.

Preformatted tapes are available which are more reliable than user-formatted tapes. Before reformatting a used tape, you must erase it with a bulk eraser. Proper use of a bulk eraser is not trivial; refer to the documentation for your bulk eraser.


getbb (F) (obsolete)
Print a list of bad tape blocks detected during the last tape operation. This listing can be saved in a file for use by the putbb command.

getblk (S)
Report the tape block size. A size of 0 (zero) implies variable block size.

getcomp (S)
Report the drive compression and decompression settings. These are either enabled or disabled.

getdensity (S)
Report the density setting of the tape drive as one of the following values:

Value Description
0 Default
1 800bpi (NRZI) (½ inch)
2 1600bpi (PE) (½ inch)
3 6250bpi (GCR) (½ inch)
4 8000bpi (GCR) (¼ inch) QIC-11
5 8000bpi (GCR) (¼ inch) QIC-24
6 3200bpi (PE) (½ inch)
7 6400bpi (IMFM) (¼ inch)
8 8000bpi (GCR) (0.15 inch)
9 37871bpi (GCR) (½ inch)
0xa 6667bpi (MFM) (½ inch)
0xb 1600bpi (PE) (¼ inch)
0xc 12690bpi (GCR) (½ inch)
0xd 25380bpi (GCR) (½ inch)
0xe Reserved forECMA
0xf 10000bpi (GCR) QIC-120
0x10 10000bpi (GCR) QIC-150
0x11 16000bpi (GCR) QIC-320/QIC-525
0x12 51667bpi (RLL) QIC-1350
0x13 61000bpi (DDS) 4mm X3B5/88-185A
0x14 54000bpi 8mm X3B5/88-036 (EXB-8200)
0x15 QIC-1000
0x22 QIC-2GB
0x7f No change

 Value   Description
 0       Default
 1       800bpi (NRZI) (½ inch)
 2       1600bpi (PE) (½ inch)
 3       6250bpi (GCR) (½ inch)
 4       8000bpi (GCR) (¼ inch) QIC-11
 5       8000bpi (GCR) (¼ inch) QIC-24
 6       3200bpi (PE) (½ inch)
 7       6400bpi (IMFM) (¼ inch)
 8       8000bpi (GCR) (0.15 inch)
 9       37871bpi (GCR) (½ inch)
 0xa     6667bpi (MFM) (½ inch)
 0xb     1600bpi (PE) (¼ inch)
 0xc     12690bpi (GCR) (½ inch)
 0xd     25380bpi (GCR) (½ inch)
 0xe     Reserved forECMA
 0xf     10000bpi (GCR) QIC-120
 0x10    10000bpi (GCR) QIC-150
 0x11    16000bpi (GCR) QIC-320/QIC-525
 0x12    51667bpi (RLL) QIC-1350
 0x13    61000bpi (DDS) 4mm X3B5/88-185A
 0x14    54000bpi 8mm X3B5/88-036 (EXB-8200)
 0x15    QIC-1000
 0x22    QIC-2GB
 0x7f    No change
Unknown density settings result in the message Unknown Density type XX.

getpart (S)
Report the active partition number of the tape drive. See the dat(HW) manual page for additional information.

getspeed (S)
Report the speed setting of the tape drive. The value returned is specific to the type of drive.

setspeed (S)
Set the speed of the tape drive. The value must be supported by the drive.

getvar (S)
Report the current setting of the Stp_read_variable_blocks switch in the device driver.

setvar (S)
Set the Stp_read_variable_blocks switch in the device driver. For example, turn the switch on by setting Stp_read_variable_blocks to 1 (one) with the -a option:

tape -a 1 setvar

To turn it off, use the -a option with an argument of 0 (zero).

When Stp_read_variable_blocks is set to 1, a read in variable mode (block size=0) returns the actual physical block read.

With Stp_read_variable_blocks set to 0, a read returns as much data as the buffer will hold.


info (I) (obsolete)
Display Irwin cartridge information. See the mcart(C) manual page for more details.

kapacity (I) (obsolete)
Report Irwin cartridge capacity in 1024-byte blocks. See the mcart(C) manual page for more details.

load (S)
Load the tape cartridge.

map (F) (obsolete)
Print out a map of the bad blocks on the tape. The format is a series of lines of the format:
track n: -------------X------...
Each ``-'' represents a good block on the track; an ``X'' represents a block marked as bad.

obeyeom (S)
Instruct the tape driver to obey the EOM (end-of-media) return code. When turned off (the default for backward compatibility), the driver returns STP_MEDIUM instead of STP_EOM when an actual EOM error is detected. When turned on, it returns STP_EOM correctly.

For example, turn the option on by setting obeyeom to 1 (one) with the -a option:

tape -a 1 obeyeom

To turn it off, use the -a option with an argument of 0 (zero).


partition (S)
Partition an SCSI tape into logical partitions 0 and 1. The size (in megabytes) of partition 1 is specified on the command line. The size of partition 0 is the remainder of the tape. For example, tape -a 200 partition creates a 200MB partition (in partition 1); partition 0 comprises the rest of the tape. For a 1300MB unformatted DAT tape, partition 0 could hold approximately 1100MB of data. (See the dat(HW) manual page for additional information.)

putbb (F) (obsolete)
Read a list of bad tape blocks from the standard input and add them to the bad block table on the tape. The format expected by putbb is the same as generated by the getbb command.

reset (C,S,F)
Reset tape controller and tape drive. Clears error conditions and returns tape subsystem to power-up state.

reten (A)
Retension tape cartridge. Should be used periodically to remedy slack tape problems. Tape slack can cause an unusually large number of tape errors.

rewind (A)
Rewind to beginning of tape (BOT). (If a SCSI tape is partitioned, the logical partition is rewound to the logical BOT. See the dat(HW) manual page for details.)

rfm (C,S)
Wind the tape forward a specified number of filemarks (using -a arg). Position the tape at the next filemark if no number is specified. A negative number moves the tape backwards that number of filemarks. Note that cartridge tapes (C) are able to wind forward only one filemark at a time.

rsm (S)
Wind the tape forward a specified number of setmarks (using -a arg). Position the tape at the next setmark if no number is specified. A negative number moves the tape backwards that number of setmarks. (See the dat(HW) manual page for more information.)

setansi (S)
Set ANSI style tape handling.

setblk (S)
Set the tape block size to a specified byte size. For example, the following command sets the tape block size to 512 bytes:

tape -a 512 setblk

Select variable block size by specifying a block size of 0 (zero).


setcomp (S)
Enable or disable tape drive compression and decompression. The values of the argument arg to the -a option select the capabilities required (depending on the drive type):

Value of arg Compression Decompression
0 disabled disabled
1 enabled disabled
2 disabled enabled
3 enabled enabled

 Value of arg   Compression   Decompression
 0              disabled      disabled
 1              enabled       disabled
 2              disabled      enabled
 3              enabled       enabled

setdensity (S)
Set the tape density to the value specified by the argument arg to the -a option. The possible values of arg are listed in the table for the getdensity command. For example, tape -a 2 setdensity selects a density of 1600bpi for a nine-track tape.

setpart (S)
Select a partition on a pre-partitioned tape. The argument arg to the -a option specifies the partition. For example, tape -a 1 setpart selects partition 1 on a tape with two partitions. (Most partitioned drives default to partition 0 on power-on or reset.) See the dat(HW) manual page for additional information.

status (C,S,F)
The status output looks like this:
status:	status message
soft errors: n
underruns: m
Status is a report of the current status of the drive; ``no cartridge'', ``write protected'', or ``beginning of tape'' are typical status messages.

Soft errors is the number of recoverable errors that occurred during the last tape operation. A recoverable error is one which is correctable by the drive or controller. An example of a non-recoverable ``hard'' error is an attempt to write to a write-protected cartridge. Note that if the number of soft errors greatly exceeds the manufacturer's specifications, the drive may require service or replacement, or you may be using a defective tape.

Underruns is the number of times the tape drive had to stop and restart due to tape buffer underflows. Underruns are not an error condition; they mean that the data transfer did not occur at the drive's maximum data transfer rate. The number of underruns can be affected by system load.

If you use the status command while the tape drive is busy, no message is displayed until the drive is free.


unload (S)
Unload the tape cartridge.

wfm (C,S)
Write arg filemarks at the current tape position. If arg is not specified, write one filemark. Note that cartridge tapes (C) are able to write only one filemark.

wsm (S)
Write arg setmarks at the current tape position. If arg is not specified, write one setmark. (See the dat(HW) manual page for more information.)

xstatus (S)
This command provides more information than the status command. The information maintained and reported is specific to the drive type; it may include number of retries, ECC corrections, and data transferred. The following is a list of all the information that may be reported:
   errors corrected without substantial delay:
   errors corrected with possible delay:
   Total errors:
   Total errors corrected:
   Total ECC errors:
   Total bytes transferred:
   Total unrecovered errors:
   Underruns:
   Overruns:
The term Underruns is described for the status command.

The term Overruns is the number of times the tape drive had to stop and restart due to the tape buffer overflowing. Overruns are not an error condition; they mean that the processor could not transfer data from the tape drive fast enough to keep the drive in streaming mode. The number of overruns can be affected by system load.

Exit values

The following exit values may be returned by tape (for Irwin drives, refer to the exit codes listed on the mcart(C) manual page):

0
Normal exit with no error.

1
Faulty cables, or no cartridge in drive.

2
Incorrect command syntax, unknown or bad tape format, unknown drive type, or device special file not found.

3
Cartridge write protected, or no data on cartridge.

4
Device in use by another process.

Examples

Display the commands available with SCSI tape drives:

tape -s

Display the commands available with Irwin tape drives:

tape -i

To obtain the status of the current (default) tape drive:

tape status

(Note: this is only applicable to QIC-02, QIC-40, QIC-80 and SCSI tape drivers.)

To retension the tape in the default drive:

tape reten

To rewind an SCSI tape (on a system where the default tape drive is some other type):

tape -s rewind

Wind an SCSI tape forward three filemarks:

tape -s -a 3 rfm

Wind an SCSI tape backward two filemarks:

tape -s -a -2 rfm

Format an Irwin tape:

tape -i format /dev/rctmini

Format a QIC-40/80 tape:

tape -f format /dev/rctmini

Files

Device special files:

/dev/rStp0 /dev/rct0 /dev/erct0 /dev/rmc1
/dev/nrStp0 /dev/nrct0 /dev/xct0  
/dev/xStp0 /dev/rct2 /dev/rctmini  
/dev/rft0 /dev/nrct2 /dev/xctmini  
/dev/xft0 /dev/xct0 /dev/rmc0  

 /dev/rStp0    /dev/rct0    /dev/erct0     /dev/rmc1
 /dev/nrStp0   /dev/nrct0   /dev/xct0
 /dev/xStp0    /dev/rct2    /dev/rctmini
 /dev/rft0     /dev/nrct2   /dev/xctmini
 /dev/xft0     /dev/xct0    /dev/rmc0
Device special files for SCSI tapes (first tape drive):

/dev/rmt/Sc0s0
linked to /dev/rStp0

/dev/rmt/Sc0s0n
linked to /dev/nrStp0

/dev/rmt/Sc0s0x
linked to /dev/xStp0

/dev/rmt/Sc0s0r

Note that if you have not installed a cartridge tape on your system, SCSI tapes device are linked to /dev/*ct0. For more information on device files, see the tape(HW) manual page.

Default configuration files:


/etc/default/mcconfig
configuration file used by mcart

/etc/default/tape
configuration file used by tape
Executable files:


/etc/mcdaemon
background service program used by mcart

/usr/bin/mcart
mcart executable file

/usr/bin/tape
tape executable file
Include files:


/usr/include/sys/tape.h

/usr/include/sys/ct.h

/usr/include/sys/ft.h

/usr/include/sys/ir.h

See also

backup(ADM), cpio(C), dd(C), mcart(C), mcconfig(F), restore(ADM), tape(HW), tar(C), xbackup(ADM), xrestore(ADM)

Standards conformance

tape is not part of any currently supported standard; it is an extension of AT&T System V provided by The Santa Cruz Operation, Inc.
© 2005 The SCO Group, Inc. All rights reserved.
SCO OpenServer Release 6.0.0 -- 03 June 2005