On Thu, 1 Sep 2005 at 10:10am, Joe Rhett wrote

> On Thu, Sep 01, 2005 at 08:52:29AM -0400, Joshua Baker-LePain wrote:
> > This can happen for a variety of reasons.  Sometimes a DLE grows between 
> > estimate time and dump time.  If you're using software compression and 
> > it's a relatively new DLE (or the nature of the data changes), amanda's 
> > estimate of the compressed size can be inaccurate.  
> 
> By 20gb?  And no, we're not using compression anywhere so that's not it.

I've had DLEs grow by over 100GB between estimate time and dump time.  
Investigate this.  Only you can figure out why that 53GB dump happened in 
the first place.

> >                                                  It's *impossible* to 
> > anticipate every situation, although I believe amanda does a pretty good 
> > job.  
> 
> Huh?  Impossible to anticipate that 53gb can't be written to a 30gb tape?

Amanda figures backups are really important, and really wants to get them 
on tape.  It knows that tapelengths can be estimates (especially if one is 
using hardware compression), and figures it'll give it a shot even if it 
doesn't look like it'll fit.

Now, I'll be the first to admit that the tape logic needs some work.  In 
the above case, it'd be nice if there were some sort of "slop" variable.  
You set it to say, 10%, and that tells taper not to bother if an image is 
>10% bigger than the amount of tapelength left.  Also, when runtapes is 
>1, it'd be nice if amanda knew that this doesn't equate to 1 tape of 
N*tapelength size, which is how I read the current code.  Unfortunately, 
I'm not much of a coder, so I can't dig in and add these.  Thus you also 
don't hear me complaining about lack of them.

> > As an aside, I really think you need to rethink your attitude.  Your 
> > subject line is incredibly unprofessional, as is your general attitude 
> > toward the amanda community.
>  
> Comes from 4 years of having the exact same discussions over and over and
> over and over again.  Why can't amanda figure out EOT when everyone else
> can?  Why doesn't it start writing the new bit to the next tape?  Don't
> point me at the FAQ, when every other bit of software has nailed this
> problem down just fine.

Tape spanning breaks one of the long held strengths/philosophies of amanda 
-- that you can do a restore with nothing but mt, dd, and tar/restore.

> And now the new best one -- if amanda is SOoooo sensitive about fitting a
> DLE onto a tape, how come it simply tries to do it without checking the
> size first?

See above.  And please, please check your attitude at the door.  If you 
want to make amanda better, join the -hackers list and get hacking.

-- 
Joshua Baker-LePain
Department of Biomedical Engineering
Duke University