Many thanks to the 9 people that responded to my question about problems I
was having with reading some data files off a tape.
Many of the suggestions ran along the lines of this response from Donald Rye:
"you might want to try /dev/rmt0l (low density) /dev/rmt0m (medium density) for
the read operation."
I had mentioned that the data was tar'ed in "low density" format, & I had
been using /dev/rmt0h to try & read the data. However, using /dev/rmt0l or
/dev/rmt0m gave me the same result as before - the "tar: [offset 0]: No
space left on device" error message.
"Harald" (hl_at_tekla.fi) suggested the following:
"No space left on device usually means the drive encountered an end of
media
condition - either the tape is completely empty or the drive isn't able
to read
the tape format.
In case I'm wrong here then I'd suggest trying to read from the tape
with
basic commands to see if there is anything at all on the tape -
od -c /dev/nrmt0h # this dumps anything that is on the tape
mt -f /dev/nrmt0h fsf # skip to the next file
if the od command outputs anything other than "0000000" then there is
someting on the tape. If the "mt fsf" fails, then there are no
additional
files on the tape, i.e. the tape is either empty (was the right tape
sent
to you?) or in some unrecognized format."
When I tried this, all I ever got was 00000000, which seems to suggest that
something is wrong with the tape or data, or there jusn't isn't any data on
the tape.
Finally, Dr. Tom Blinn <tpb_at_zk3.dec.com> had the following suggestions:
"wonder whether there are some kind of tape marks or empty files on the
tape that you don't know are there.
The tapex utility (in /usr/field/tapex, one of the system exercisers) has an
option to read a tape and provide a listing of the files and record sizes.
In a case like this, I'd want to run it against the tape (it's a read only
non-destructive test) and see what it reports.
There is also an older version of tar in the "obsolete commands and
utilities" subset that might read the tape.
The "tar" in V4.0B does have some bugs, and one of them might be causing the
error you're seeing."
I don't have a tapex directory under /usr/field, so I wasn't able to try
that. I decided to return the tape & try another transfer medium (ftp or
CD-R), so hopefully that will fix this little problem.
Many thanks to the other people that also responded.
Sincerely,
Colin Brooks
****************************************************
Colin Brooks
GIS Programmer Analyst
Integrated Hardwood Range Management Program
Hopland Research & Extension Center
4070 University Rd.
Hopland, CA 95449
Primary #'s - TEL:(707)744-1270 FAX:(707)744-1040
Work E-mail: cbrooks_at_nature.berkeley.edu
http://danr.ucop.edu/ihrmp
http://www.pacific.net/~cbrooks/gis1.shtml
I'm also found at:
ESPM, University of California - Berkeley
160 Mulford Hall
Berkeley, CA 94720-3114
Secondary #'s - TEL: 510-643-1136 FAX: 510-643-5438
****************************************************
Received on Sat Oct 18 1997 - 03:08:15 NZDT