1SCSITAPE(1) General Commands Manual SCSITAPE(1)
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6 scsitape - control SCSI tape devices
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9 scsitape [-f <scsi-generic-device>] commands
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12 The scsitape command controls SCSI tape drives in a platform-indepen‐
13 dent manner. As long as 'mtx' works on the platform, so does 'scsi‐
14 tape'.
15 Note that 'scsitape' and your OS's native tape driver may stomp on each
17 other. In particular, if you use 'setblk' and your OS's native tape
18 driver has a different notion of the block size, you may get evil
19 results. It is recommended to use 'scsitape' only for software where
20 you've written your own low-level READ and WRITE routines that use the
21 SCSI command set to directly talk to tape drives (i.e., you do not use
22 the OS's native tape driver at all).
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25 The first argument, given following -f , is the SCSI generic device
26 corresponding to your tape drive. Consult your operating system's doc‐
27 umentation for more information (for example, under Linux these are
28 generally /dev/sg0 through /dev/sg15, under FreeBSD these are
29 /dev/pass0 through /dev/passX. Under Solaris this is usually the same
30 as your tape drive (Solaris has a SCSI passthrough ioctl). You can set
31 the STAPE or TAPE environment variable rather than use -f.
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34 setblk <n>
35 Set the tape drive's SCSI block size to <n> bytes. (NOTE: if
36 you are using your OS's native tape driver, THIS IS EVIL!).
37 fsf <n> Go forward by <n> tapemarks.
40 bsf <n> Go to immediately previous the <n>th previous tapemark.
42 (WARNING: This probably doesn't do what you expect -- e.g. if
43 you are immediately after a tapemark and type 'bfs 1', it
44 moves to immediately *before* that tape mark, for a sum total
45 of zero effective movement!).
46 eod Go to end of data.
48 rewind Rewind the tape drive.
50 eject Eject the tape currently in the drive.
52 erase Does a *short* erase (warning: does NOT work on all drives!).
54 mark <n>
56 write <n> filemarks ( 'mark 0' flushes the drive's buffers
57 ).
58 seek <n> Seek to a logical position <n> that was reported by a previ‐
60 ous 'tapeinfo' command.
61 write <blocksize>
63 write blocks from stdin to the tape. Chunk the data into
64 <blocksize>-sized chunks. *DOES NOT WRITE OUT A TAPEMARK!*
65 (you will need to use a subsequent mark 1 command to write
66 out a tape mark).
67 read [<blocksize>] [ <#blocks/#bytes> ]
69 read blocks from the tape, write them to stdout. If we are in
70 variable block mode, <blocksize> should be zero (note: The
71 maximum block size we currently support in variable block
72 mode is 128K, MAX_READ_SIZE will need to be turned into a
73 settable variable to allow bigger reads). If <blocksize> is
74 ommitted, we assume that we're in variable block mode, and
75 that we are going to read from tape until we hit a tapemark
76 or end of partition or end of tape.
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81 This program was written by Eric Lee Green <eric@badtux.org>. Major
82 portions of the 'mtxl.c' library used herein were written by Leonard
83 Zubkoff.
84 The SCSI read and write routines are based upon those that Richard Fish
86 wrote for Enhanced Software Technology's BRU 16.1 product, substan‐
87 tially modified to work in our particular environment (in particular,
88 all the variable block stuff is new since BRU only does fixed block
89 reads and writes, and the BRU code uses bitmasks rather than bitfields
90 for the various flags and such in return values, as well as the BRU
91 code having a different SCSI API and having variable names considerably
92 shorter than the rather sesquipedalian 'mtx' identifiers). As required
93 by 'mtxl.c', these routines are licensed under the GNU General Public
94 License.
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98 Under Linux, cat /proc/scsi/scsi will tell you what SCSI devices you
99 have. You can then refer to them as /dev/sga, /dev/sgb, etc. by the
100 order they are reported.
101 Under FreeBSD, camcontrol devlist will tell you what SCSI devices you
103 have, along with which pass device controls them.
104 Under Solaris 7 and 8, /usr/sbin/devfsadm -C will clean up your
106 /devices directory. Then find /devices -name 'st@*' -print will return
107 a list of all tape drives. /dev on Solaris is apparently only of his‐
108 torical interest.
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112 for scsitape read 0 <n> where you are doing variable-block-size reads
113 and wish for <n> bytes, it instead reads one and exactly one block from
114 tape and prints that (no matter what its size). Use 'dd' on the output
115 of scsitape if you want finer control.
116 scsitape read 0 attempts reads of MAX_READ_SIZE, which is currently
118 128K. If blocks on tape are larger than 128K, only the first 128K will
119 be read -- the remainder will be silently dumped in the toilet.
120 This program does not interact well (or at all :-) with your OS's
122 native tape driver. You will likely see weird things happen if you
123 attempt to intermingle scsitape commands with native tape driver opera‐
124 tions. Note that BRU 16.1 for Solaris (and possibly others, but Solaris
125 I know about) will have a 'scsi' keyword to bypass the native tape
126 driver and write via direct uscsi commands, so if you use ´scsitape´ to
127 bypass the flaws of the native Solaris driver, you can use BRU 16.1 to
128 write your actual tape archives. (Assuming that BRU 16.1 has been
129 released at the time that you read this).
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133 This version of scsitape is currently being maintained by Robert Nelson
134 <robertnelson@users.sourceforge.net> as part of the 'mtx' suite of pro‐
135 grams. The 'mtx' home page is http://mtx.sourceforge.net and the actual
136 code is currently available there and via SVN from http://source‐
137 forge.net/projects/mtx.
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141 loaderinfo(1),tapeinfo(1),mtx(1)
142 SCSITAPE1.0 SCSITAPE(1)