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copytape.1.man
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COPYTAPE(1)
NAME
copytape - duplicate magtapes
SYNOPSIS
copytape [-f] [-t] [-s_n_n_n] [-l_n_n_n] [-v] [_i_n_p_u_t [_o_u_t_p_u_t]]
DESCRIPTION
_c_o_p_y_t_a_p_e duplicates magtapes. It is intended for duplica-
tion of bootable or other non-file-structured (non-tar-
structured) magtapes on systems with only one tape drive.
_c_o_p_y_t_a_p_e is blissfully ignorant of tape formats. It merely
makes a bit-for-bit copy of its input.
In normal use, _c_o_p_y_t_a_p_e would be run twice. First, a boot
tape is copied to an intermediate disk file. The file is in
a special format that preserves the record boundaries and
tape marks. On the second run, _c_o_p_y_t_a_p_e reads this file and
generates a new tape. The second step may be repeated if
multiple copies are required. The typical process would
look like this:
tutorial% copytape /dev/rmt8 tape.tmp
tutorial% copytape tape.tmp /dev/rmt8
tutorial% rm tape.tmp
_c_o_p_y_t_a_p_e copies from the standard input to the standard out-
put, unless input and output arguments are provided. It
will automatically determine whether its input and output
are physical tapes, or data files. Data files are encoded
in a special (human-readable) format.
Since _c_o_p_y_t_a_p_e will automatically determine what sort of
thing its input and output are, a twin-drive system can
duplicate a tape in one pass. The command would be
tutorial% copytape /dev/rmt8 /dev/rmt9
OPTIONS
-s_n_n_n
Skip tape marks. The specified number of tape marks are
skipped on the input tape, before the copy begins. By
default, nothing is skipped, resulting in a copy of the
complete input tape. Multiple tar(1) and dump(1)
archives on a single tape are normally separated by a
single tape mark. On ANSI or IBM labelled tapes, each
file has three associated tape marks. Count carefully.
-l_n_n_n
Limit. Only nnn files (data followed by a tape mark), at
most, are copied. This can be used to terminate a copy
early. If the skip option is also specified, the files
skipped do not count against the limit.
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COPYTAPE(1)
-f From tape. The input is treated as though it were a phy-
sical tape, even if it is a data file. This option can
be used to copy block-structured device files other than
magtapes.
-t To tape. The output is treated as though it were a phy-
sical tape, even if it is a data file. Normally, data
files mark physical tape blocks with a (human-readable)
header describing the block. If the -t option is used
when the output is actually a disk file, these headers
will not be written. This will extract all the informa-
tion from the tape, but _c_o_p_y_t_a_p_e will not be able to
duplicate the original tape based on the resulting data
file.
-v Verbose. _c_o_p_y_t_a_p_e does not normally produce any output
on the control terminal. The verbose option will iden-
tify the input and output files, tell whether they are
physical tapes or data files, and announce the size of
each block copied. This can produce a lot of output on
even relatively short tapes. It is intended mostly for
diagnostic work.
FILES
/dev/rmt*
SEE ALSO
ansitape(1), dd(1), tar(1), mtio(4), copytape(5)
AUTHOR
David S. Hayes, Site Manager, US Army Artificial Intelli-
gence Center. Originally developed September 1984 at
Rensselaer Polytechnic Institute, Troy, New York. Revised
July 1986. This software is in the public domain.
BUGS
_c_o_p_y_t_a_p_e treats two successive file marks as logical end-
of-tape.
The intermediate data file can consume huge amounts of disk
space. A 2400-foot reel at 6250-bpi can burn 140 megabytes.
This is not strictly speaking a bug, but users should be
aware of the possibility. Check disk space with _d_f(_1)
before starting _c_o_p_y_t_a_p_e. Caveat Emptor!
A 256K buffer is used internally. This limits the maximum
block size of the input tape.
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