This is the mail archive of the cygwin mailing list for the Cygwin project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: mt and tar fail on LTO-5 drives


On 08/20/2013 11:05 AM, Corinna Vinschen wrote:
On Aug 20 10:29, Corinna Vinschen wrote:
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
Make that

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

I wrote the setpart and mkpart commands before mt on Linux had them and
naturally they are now using different strings.  I'll have another look
into mt to make it more compatible with mt on Linux.


Well, Corinna, you really saved the day. I missed the partition stuff completely.

    $ mt -f /dev/nst0 status 2
    drive type       :       56 (STK 9840)
    tape capacity    : 1419369472 KB remaining        : 1324161024 KB
    current file     :       -1             active partition :        1
    current block    :       -1             cur logical block:   195351
    General status bits on (1090000):
      ONLINE IM_REP_EN HW_ECC
    min block size   :        2             max block size :   524288
    def block size   :   131072             cur block size :        0
    density code     :       58 (Ultrium LTO-5)


Thanks, I think we can close this one!

- Bartels



--
Problem reports:       http://cygwin.com/problems.html
FAQ:                   http://cygwin.com/faq/
Documentation:         http://cygwin.com/docs.html
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]