Re: mt and tar fail on LTO-5 drives

[Corinna Vinschen <corinna-cygwin at cygwin dot com>]

On Aug 19 21:10, bartels wrote:
> On 08/19/2013 07:12 PM, Corinna Vinschen wrote:
> >
> >It would be interesting to see the OS error codes.  If you run tar under
> >strace, the trace output should contain a line like
> >
> >   [...] write: Win32 error XXXX
> >
> >or
> >
> >   [...] close: Win32 error XXXX
> >
> >The value of XXXX is what I'm curious about.
> 
> Here is the error:
> 
>  15692 21364024 [main] tar 5700 mtinfo_drive::error: write: Win32 error 1100

ERROR_END_OF_MEDIA.  The OS really thinks the medium is at its end...

...or the *partition* is at its end.  Something occured to me this
morning.  Are you using used tapes, rather than fresh ones?  Are the
tapes you're using partitioned, by any chance, maybe because LTFS
partitions the tape in two partitions, one for the files and one for
metadata?

This would explain the low capacity you see in mt status output.  If the
tape is partitioned, the capacity returned by GetTapeParameters is not
the size of the entire tape, but the size of the current partition(*).
And partition 0 is probably the metadata partition.

This also explains why you get a supposedly early ERROR_END_OF_MEDIA.
The partition is just not bigger.

Try this:

  $ mt -f /dev/nst0 setpartition 0
  $ mt -f /dev/nst0 status 2
  $ mt -f /dev/nst0 setpartition 1
  $ mt -f /dev/nst0 status 2

> >>I suppose there is nothing for cygwin to do, other
> >>than adding some items to the 'density' list:
> >>   {0x44, "Ultrium LTO-3"},
> >mt already knows LTO-3 and 4.
> 
> Which version is that? I have mt V2.3.2 and do not see it in the code.

The current version is 2.3.3.  I'll release a 2.3.4 soon.


Corinna


(*) http://msdn.microsoft.com/en-us/library/windows/desktop/aa362526%28v=vs.85%29.aspx

-- 
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Maintainer                 cygwin AT cygwin DOT com
Red Hat

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