tcopy
—
copy and/or verify mag tapes
tcopy |
[-cvx ] [-s
maxblk] [src
[dest]] |
The tcopy
utility is designed to copy magnetic tapes.
The only assumption made about the tape layout is that there are two
sequential EOF marks at the end. By default, the tcopy
utility will print information about the sizes of records and files found on
the /dev/sa0 tape, or on the tape specified by the
src argument. If a destination tape is also specified by
the dest argument, a copy of the source tape will be
made. The blocking on the destination tape will be identical to that used on
the source tape. Copying a tape will yield the same program output as if just
printing the sizes.
The following options are available:
-c
- Copy src to dest and then
verify that the two tapes are identical.
-s
maxblk
- Specify a maximum block size, maxblk.
-v
- Given the two tapes src and
dest, verify that they are identical.
-x
- Output all informational messages to the standard error instead of the
standard output. This option is useful when dest is
given as /dev/stdout.
The tcopy
command appeared in
4.3BSD.
- Writing an image of a tape to a file does not preserve much more than the
raw data. Block size(s) and tape EOF marks are lost which would otherwise
be preserved in a tape-to-tape copy.
- End of data (EOD) is determined by two sequential EOF marks with no data
between them. There used to be old systems which typically wrote three
EOF's between tape files. The
tcopy
utility will
erroneously stop copying early in this case.
- When using the copy/verify option
-c
,
tcopy
does not rewind the tapes prior to start. A
rewind is performed after writing, prior to the verification stage. If one
does not start at the beginning-of-tape (BOT) then the comparison may not
be of the intended data.