On Saturday 24 January 2004 13:28, Jon LaBadie wrote:
>On Sat, Jan 24, 2004 at 01:17:43PM +1100, Jobst Schmalenbach wrote:
>> I try next week to write a little shell script which takes the
>> *first* 32 block, dumps it to a file, reads is, and starts writing
>> on the first zero, appends the TOC (as in tar
>> location/filemarks/date) making sure not writing past the 32K and
>> dumps it back to to the tape.
>> I think using a "mt -f /dev/tape rewind" or "mt -f /dev/tape asf
>> 0" should me put me onto the beginning of the header block.
>> Then I will check whether AMANDA still recognises this tape as an
>> AMANDA tape ...
>
>What you will know if whether it works on YOUR setup.
>Your findings will not generalize to someone else's.
>Different tape formats (DLT, AIT, DDS[234], ...)
>may all react differently.  And I don't know if there
>is an impact from the tape driver in the OS.  If so
>that may influence things also.

I don't think amanda will have any problems recognizing its tape from 
the method he's describing Jon, but the data already on that tape 
will probably be lost forever.  Success there would indeed surprise 
me.  The first thing he would have to do is use the rewinding device 
in order to force the flush to media that would cause at the end of 
the write.  My drives have never had a seperate buffer flush command 
that I know of.

With the exception of that one dec tape drive someone mentioned, or 
maybe a space heating old tank of a 9 track reel to reel, they are 
not what one would normally want to treat as a random access r/w 
devices.

-- 
Cheers, Gene
"There are four boxes to be used in defense of liberty: soap,
ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
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Copyright 2004 by Maurice Eugene Heskett, all rights reserved.