Copyright ©1997 Peter Urbanec. All rights reserved
EMail: peteru@null.net Phone: +61 2 9398 3456 Snail: Peter Urbanec PO Box 752 Randwick NSW 2031 AUSTRALIA
tape (all lowercase) is a command line tool to control the TAPE device driver for SCSI-2 tape devices.
This document describes version 1.01 of the tape utility.
The tape tool provides a way for you to control the TAPE device driver from the terminal. It allows you to display information about the device driver and the tape drive as well as providing ways of manipulating the media and changing the drive settings.
These are the command line arguments supported by the program:
Usage: tape TAPE_DEVICE cmd [arg] commmands: info - show device info eject - spit tape out rewind - position at BOM buffer - enable buffered operation nobuffer - disable buffered operation compress - enable data compression nocompress - disable data compression blocksize - report valid range for size of blocks move [-]arg - move arg files forward (backward if arg is negative)
The devices are named /dev/scsi/tape/XYZ
, where X
is the
bus number and can range from 0 to 9. Y
is the target number, also
known as the SCSI id of the device. It can range from 0 to 7 for standard 8-bit
SCSI configurations and from 0 to F (ie. all valid hex digits) for exclusively
WIDE SCSI configurations. Z
is the logical unit number, also known
as LUN. Some tape libraries use the LUN to select which tape to use. Normal desktop
style tape drives usually only respond to LUN 0.
Info will display several fields worth of information. They are:
Eject attempts to physically eject medium from the drive if the device is capable of this. An eject often (not always) implies a rewind of the medium.
Rewind returns when the medium has been positioned at the beginning of recordable area.
Do not change the default buffering setting carelessly. Turning off buffering might prevent a device from streaming data, resulting in horrible performance, waste of tape, excessive repositioning and unnecessary wear on the mechanism.
Since most drives default to the best speed / capacity configuration, you should not need to change the compression setting. In rare circumstances, you might want to disable compression to achieve backward compatibility with older drives. Note that not all drives support compression. Some devices do support compression, but may not honour this flag. A notable example of this is the SONY SDT-5000 drive.
Blocksize reports the range of block sizes supported by the tape drive. Tape drives which only support fixed size blocks will return the same number in both variables. The maximum block size achievable is 16 MB.
Move will cause the medium to be re-positioned arg
filemarks from the
current position. Negative numbers will move backwards, positive numbers will move
forwards. The resulting position will be the begining of the first block after the
filemark.
If there are any errors encountered during the communication with the device, the program will report them. The fields which are printed are important for debugging purposes and may not make much sense to you. The message field should however provide you with a plain english representation of the reason for failure.
When reporting bugs or incompatibilities, please include the following information:
"tape DEVICE_NAME info"
command.