I think the basic problem that you have had, and it seems like you don't quite 
understand though you have found a solution, is that recycling for Bacula 
requires applying two concepts: 1. the time Bacula can write on a Volume, 2. 
the time Bacula keeps that Volume before reusing it.

Most people come with the pre-conceived idea that there is one "Recycle" time, 
when in fact Bacula is significantly more sophisticated than that.

I've reviewed the chapter you refer to below, and if one reads the full 
chapter, all the information *is* there (at least IMO).  I have added 
additional text that stresses the above two concept points a bit more  as 
well as refer the user to the "Basic Volume Management" chapter that gives a 
detailed practical example of why you want to do.  The Recycle chapter is 
complete in itself assuming you want to fill all your Volumes.  If not, you 
must also read the Basic Volume Management chapter as well.

Concerning your comment:
    "Can someone please update the documentation here 
     http://www.bacula.org/rel-manual/Automatic_Volume_Recycling.html
     with this information, that should hopefully forestall this question       
  
     coming up so much."

I appreciate you pointing out where you got confused.  However, this is a free 
software project, and I understand recycling, so I don't easily see why some 
people don't get the concepts or I would have already changed the doc.  As a 
consequence it is much more helpful if you would submit a suggested change to 
the documentation that clarifies it for you.

I suggest you look at the documentation in:

http://www.bacula.org/dev-manual/Automatic_Volume_Recycling.html

It is usually much more up to date.

On Saturday 17 December 2005 07:00, Harondel J. Sibble wrote:
> On 16 Dec 2005 at 1:25, Arno Lehmann wrote:
> > > ....so....how does one force it to do it?!
> >
> > Apart from the configuration directives like "prune oldest volume" (or
> > something) my advice is usually "you don't".
>
> Philisophical disagreement, If I as the admin decide that, that is an
> appropriate thing to do, I should be able to do it in some manner. Reminds
> me of the unix philosophy, build a bunch of single purpose tools that you
> can chain together to do anything you want .....
>
> Anyhow, on the how to do it, here's what I got from an unrelated list where
> I was ranting about the same problem the OP has as I had it for months
> also.
>
> What you need is this
>
> Volume Use Duration =
>
> added to your pool definition where the duration is equal to or less than
> your Volume Retention setting, in my case the relevant lines are
>
> Volume Retention = 6d
> Volume Use Duration = 6d
>
> With this setup, Bacula FINALLY works like I expect and how pretty much any
> other backup software I've used on Windows or Unix works.  It will
> overwrite the tape in the drive, assuming 6 days has passed, it marks the
> tape as used and then recycles it, however it only does that at the
> beginning of the next job, so the recycling happens at the start of the
> current job. Can someone please update the documentation here
>
> http://www.bacula.org/rel-manual/Automatic_Volume_Recycling.html
>
> with this information, that should hopefully forestall this question coming
> up so much.
>
> >From the messages on tonights job
>
> 16-Dec 21:30 fileserver-dir: Start Backup JobId 70,
> Job=Company-Fileserver_Full_Back 16-Dec 21:30 fileserver-dir: Recycled
> current volume "Friday3"
> 16-Dec 21:30 fileserver-sd: Recycled volume "Friday3" on device "DDS-4"
> (/dev/ns
>
> This is the first week since the beginning of the year where I've not had
> to manually purge the tapes each day.
>
> > > Think: if the tape goes full after 3 jobs, and I have 4 each night, my
> > > last job will not be done.
> >
> > Or, in other words, you need enough space available.
>
> Yes, that makes perfect sense.
>
> > No, this is,in my opinion, the best way to handle backups: Avoid
> > overwriting valid data whenever possible.
>
> If I setup a rotation, I should be able as the administrator to decide what
> is the appropriate retention time
>
> > Well, your assumption is not coherent with Bacula, then. Bacula treats a
> > retention like "keep the data for at least this time. Only after this
> > time has passed consider recycling that volume." Thus, you should assume
> > that your data will not be overwriten until 12 days have passed after the
> > last job on a given volume is finished.
>
> In my experience, it still doesn't work, even 5 weeks later when I have a 6
> day retention period, I still have to manually purge the tape.
>
> > Hmm. Isn't that how Bacula works? If a volume is in the right pool,
> > and it is flagged as recyclable, and automatic pruning for the jobs
> > and volumes is on, AND the retention period has passed, the volume
> > will be considered when Bacula looks for a recyclable volume.
>
> The key thing for the OP to remember is that bacula will not recycle the
> current volume if any other appendable volumes exist, seems odd to me, but
> that is how it is. However, from a practical pov, using the volume use
> duration statement seems to get around that just fine.
>
> > If you want to limit the time Bacula uses a volume, you can do so by
> > setting the proper volume use time or number of jobs.
>
> Yes, that needs to be added to the docs.
>
> > If I set up a pool to have backups available for a certain time, and
> > I've not got enough volumes, Bacula tells me so. Either I re-think my
> > backup strategy and modify the setup, or I buy more tapes.
>
> Even with that setup, it still doesn't recycle properly. I've seen this in
> several instances where I've followed the chapter on automatic volume
> recycling in the manual, until I was shown the info at the beginning of
> this email, I was looking at dumping Bacula, which is a GREAT piece of
> software, but for this one problem.
>
> Considering the frequency that this problem is asked about, I'd say there
> is definately a conceptual issue at hand.

-- 
Best regards,

Kern

  (">
  /\
  V_V


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