(Original question is included at the end.)
Hello,
Several respondents assumed that the VMS tape in question
contained VMS backup data, in which case the block size would be 8192.
For people interested in reading VMS backup tapes, the following programs
may be useful (not tested by me!):
vmsbackup - freeware, reads VMS backups?
ftp://www.decus.org/pub/lib/vs0185/vmstar/vmstar.zip
- identifies which VMS utility created the tape
Instead, the tape contained regular files written using a block
size of 49152 which exceeds the maximum ANSI-compliant block size (20k)
for a labeled tape, as many people noted. Since the tape's contents could
not be recreated, I needed a utility which could deal with the nonstandard
block size.
Several people suggested using "mt" to skip over the tape label
and then using "dd" to copy the data off of the tape to disk. The utility
/usr/field/tapex may also be useful for verifying the block size and recl
used on the tape.
Finally, Dr. Tom Blinn saved the day by compiling for me a special
version of ltf with an increased maximum block size limit. Tom notes that
the current size limit is a relic of the ULTRIX-32 version of the program.
I will open a problem report with Digital Support in order to get this
maximum size changed to something appropriate for DU.
In the meantime, if anyone would like this "special" version of
ltf, feel free to contact me. It works just fine.
Dave Wolinski
wolinski_at_umaxp1.physics.lsa.umich.edu
Thanks to the following people, listed in order of response:
Sherman Owens
Nathan P Shaw
Dr. Tom Blinn
Alan Rollow
Dick Seymour
malonsom_at_villacero.villacero.com.mx
Lucio Chiappetti
Girish Phadke
Stefan Karlsson
-------------------------------------------------------------------------------
Original question:
Has anyone been able to read tape files created by a VMS machine?
I'm trying to use a EXB-85058 8mm tape drive to copy some files from a
tape created under VMS. We are currently using Digital Unix 4.0B.
I've tried using the "ltf" (labeled tape facility) command, and I
can at least successfully list the files on the tape:
> ltf -tvf /dev/nrmt0h
ltf: Volume ID is: CCK676 Volume is: ANSI Version 3
ltf: Owner ID is:
ltf: Implementation ID is: unix
t(1,1) --------- -/- Sep 9 1994 17(49152)F
b57730a_.qj2b_5p
....etc.
But I can't copy files from the tape:
> ltf -xvf /dev/nrmt0h
ltf: Volume ID is: CCK676 Volume is: ANSI Version 3
ltf: Owner ID is:
ltf: Implementation ID is: unix
ltf: FATAL > Invalid block size. Min = 18 bytes, Max = 20480 bytes
I think that ltf doesn't like the block size of 49152 which was
apparently used to create the tape on the original VMS system.
Any advice or suggestions are appreciated!
Received on Fri Mar 20 1998 - 02:58:30 NZST