[Info-vax] Delete a file from a tape?

[Christoph Gartmann]

In article <Bsn1WPrTcao1 at eisner.encompasserve.org>, koehler at eisner.nospam.encompasserve.org (Bob Koehler) writes:
>In article <hb2s13$2pu$1 at news.belwue.de>, gartmann at nonsense.immunbio.mpg.de (Christoph Gartmann) writes:
>> Hello,
>> 
>> I have a tape with a few files (backup savesets). The last file on tape is
>> an incomplete saveset. Thus, I would like to delete this last file from the
>> tape. But OpenVMS 7.3-2 lists the file, asks for confirmation to delete and
>> finally refuses to do so. My next attempt was to recreate the saveset in
>> question via BACKUP with /REPLACE. Here I got:
>> 
>> %BACKUP-F-POSITERR, error positioning MKB200:[000000]13OCT09MAC358.BCK;
>> -SYSTEM-F-OPINCOMPL, operation is incomplete
>> 
>
>   Do you know how many files are on the tape, prior to the partial
>   file?  If not you can mount the tape as a labeled tape and use
>   DIRECTORY to count the files, but ask for enough directory
>   information to force an output line for each file.  You'll have to
>   abort the operation when the tape drive reads the EOV mark.
>
>   Then mount the tape /foreign.  Use "set magtape/skip=file:x" where
>   x is 3 times the number of backup save sets you want to keep.  Then
>   "set magtape/end_of_file" twice.
>
>   That will make the tape logically end after the last full saveset.

Ok, I thought this would do the trick. But after the operation I got
the following error when trying to backup further onto this tape (a DLT600):

%MOUNT-I-MOUNTED, MAC02 mounted on _MPI3$MKB200:
%BACKUP-F-POSITERR, error positioning MKB200:[000000]13OCT09MAC358.BCK;
-SYSTEM-F-OPINCOMPL, operation is incomplete

Thus, I ended up copying the savesets to disk, initializing the tape (using
/ERASE) and copying back the savesets to tape.

Regards,
   Christoph Gartmann

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