Thanks to all who replied.
The original question was:
> I need to read a tar file produced on a TLZ07 tape unit (no special
> options on the tar command) on a TLZ04 tape unit.
> Are there any special option to use on the TLZ04 unit to read this
> TLZ07 tape (like blocksize ????).
> When i just do a "tar -tvf /dev/rmt0h" i get the message:
> "tar: [offset 0]: No space left on device"
>
> Any suggestions ?
Quoting three of the people who replied will give a good summary of the
problem
and possible solutions:
alan_at_nabeth.cxo.dec.com replied:
You'd better not be using tapes longer than 60 meters on
the TLZ04. The TLZ04 is as likely to mangle the longer
tapes as it is to not read them. With a suitable length
tape, you should be able to write one that will be readable
on the TLZ04 if you don't use hardware compression. That
should be a simple matter of picking the right special
device when writing the tape.
Dr. Thomas P. Blinn replied:
The TLZ04 can only read "uncompressed" tapes, and only the 60m length,
not the 90m or 120m that are compatible with the TLZ07. On the TLZ07
you MUST record the tape using either the "a" or "l" device name, so
that hardware compression will be turned off. This is all documented
in some manpage, but it's not necessarily really obvious how to get it
working. You do need to know the characteristics of both tape drives.
The reason you're getting the error message is because the tape isn't
recorded in a format compatible with the TLZ04, so it concludes there
isn't any data on the tape.
John Francini replied:
The problem is that the TLZ04 drive does not support compression, nor
does it support DDS-2 or DDS-3 tape format, nor does it support 120
or 90 meter length tapes. It was a first-generation DAT drive.
If the tape was originally written using a device name ending in h
(like /dev/rmt0h), the tape uses hardware compression.
Your ONLY chance to write a tape on the TLZ07 that the TLZ04 can read
is to do the following:
1. Use a tape no longer than 60 meters.
2. Do not use compression -- write to a tape device name ending in a,
such as /dev/rmt0a. See tz(4) for info on tape densities and device
names.
Maurice Steyvers
Received on Thu Jan 27 2000 - 07:50:17 NZDT