Amanda-Users

Re: More than one tape per run

2003-10-24 10:35:49
Subject: Re: More than one tape per run
From: Jon LaBadie <jon AT jgcomp DOT com>
To: amanda-users AT amanda DOT org
Date: Fri, 24 Oct 2003 10:29:33 -0400
On Fri, Oct 24, 2003 at 10:12:03AM +0200, Toralf Lund wrote:
> 
> >>>
> >>Ah, I see. So it won't actually multiply tape size by runtapes when 
> >>trying to figure out how much it can write... I'm not sure the 
> >>functionaltiy is of much use to me then, but perhaps I could cheat and 
> >>pretend the tapes are "runtapes" times larger than they really are?
> >>
> >>
> >Won't buy you anything.  Amanda will reach the actual end of the tape
> >and not be able to go on to a second tape because runtapes is 1.
> > 
> >
> What I meant was set, say, length (in tape config) = 2*<actual tape 
> size>  *and* runtapes = 2.
> 

Lying to amanda is not nice :)  And again won't buy you anything.

Hypothetical, 1 DLE, 1.5GB, a tape with an actual capacity of 1.0GB.

You set tape length to 1GB and runtapes to 1.
Amanda notes the impossibility of taping this and may refuse to do a level 0.

You leave tape length to 1GB and runtapes to 6.
Amanda continues to note the impossibility of taping that DLE.

You lie and set tape length to 2.0GB and runtapes to anything, but say 3.
Amanda does the dump of 1.5GB but hits end of tape (EOT) at 1.0GB.
It thinks there might have been a tape error because the admin said the
tape was 2.0GB so it tries the allowed tape 2 by starting to tape the dump
from the beginning.  And hits EOT again.  The same error is encountered
on every tape you allow amanda to use.  You waste tons of taping time
doing an impossible task; fitting a 1.5GB dump into a 1.0GB box.

-- 
Jon H. LaBadie                  jon AT jgcomp DOT com
 JG Computing
 4455 Province Line Road        (609) 252-0159
 Princeton, NJ  08540-4322      (609) 683-7220 (fax)