On Wednesday 10 August 2005 13:49, Brian A. Seklecki wrote:
>On Tue, 9 Aug 2005, Gene Heskett wrote:
>> On Monday 08 August 2005 22:41, Marcus wrote:
>>> I've been messing around with chg-mtx and chg-scsi and
>
>[..snip...]
>
>> If you installed from the tarball (highly recommended) then there
>> should be samples of these files in the src tree 'example'
>> directory. There are 25 files in there from my latest build of
>> 2.4.5-20050711 but unforch I do not see a chg-mtx.conf among them.
>>  However in the 'docs' directory, see 'tapechangers.txt' which
>> might be helpfull as
>
>What the docs don't make clear is the fact that *only* chg-scsi
> complex variants use a changer.conf.  chg-chio and chg-mtx for
> example, are relatively simplistic perl or bourne shell wrapper
> scripts, that do not. Also, chg-mtx requires a "tapefile" config
> and chg-chio does not (which is obvious from looking through the
> source code).
>
>On the same accord, chg-chio and chg-mtx also lack support for
> hardware / platform independant barcode reader support.
>
>Amanda really needs to cache the changer's "status" / barcode
> meta-data in a psuedo database somewhere to prevent the need to
> cycle the entire changer.
>
>~BAS

What bothered me about using chg-scsi in my setup was that somewhere
in the data path, rewind commands were gobbled up, rendering amcheck
worthless unless you issued an 'mt -f /dev/nst0' rewind in front of
it, and behind it so that when amdump went to check the tape, it could
find that the label was ok and use it.  Otherwise it cycled thru the
magazine looking for the right tape, but never actually reloaded the
one it found in the drive in the first place, at which point it would
have found it had the right tape to start with since the reload would
have rewound it.

This puts a lot of war and tear on the tapes and on the changer too,
probably having something to do with my own relatively poor
experience with that Seagate changer.  Even weirder, when it found
the right label, its supposed to rewind it, and rewrite it with the
new date, but because the rewind didn't work, you actually wound up
with 2 label blocks written to the header of the tape, I verified that
little item many times.

Unforch, it appears that chg-scsi is now unmaintained as Thomas
Hepper hasn't surfaced on this list in 2-3 years now.  He was the
last one to work on it I believe as I gave him root on my box at work
so he could see if it could be improved.  That was back in '99 maybe,
but see the ChangeLog to be sure.

If you are good at sorting spagetti code, please take a look at
chg-scsi and see if its worth salvaging.  I can often fix well
organized code, because the organization makes it easy for this old
man to visualize the codes flow.  But thats spagetti, and I'm lost 40
lines into it.

-- 
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)
99.35% setiathome rank, not too shabby for a WV hillbilly
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Copyright 2005 by Maurice Eugene Heskett, all rights reserved.