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Re: [Bacula-devel] Vbackup feature

> 5. Like the Migration and Copy jobs, the input Pool (from where it
> the
> currently backed up data) and the output Pool (where it writes the
> data) must be different.  This ensures that the job does not attempt
> read
> and write to the same device, which just will not work.

The key point is that Migration/Copy/vBackup/whatever jobs need to be
able to force the selection of a *different* volume in the specified
pool for output, regardless of whether it is the same pool or a
different pool. If that capability is available, the scenario you
discuss is no longer a problem (and it fixes the ability to consolidate
tapes easily within a pool, as long as there is spare space on *a*
volume in the pool different than the one you're reading from).

> However, it is much more likely that you will then continue doing
> incremental
> backups (no more Full or Diffs).  At some point later, you want to do
> another
> vbackup to "consolidate" all the Inc backups, and now the process
> because you are going to need to read from Pools P2 (Full produced by
> vbackup) and P1 (new Incs), and you will attempt to write to P2, which
> will
> not work.
> Thus without some other mechanism to move Volumes from Pool to Pool, a
> setup
> like described above won't work, and I suspect this is what will be
> the
> most frequently (i.e. do only one Full and there after vbackups when
> are enough Incs to warrant a consolidation).

I would argue that your Vbackup becomes the basis for any future
incrementals and the previous jobs are deleted -- think of it as a
"bring the base up to *this* point in time, and then start work from

This is effectively what TSM does, and it works pretty well. It implies
at some point you will need versioning of objects/files if you want to
allow people to go back in time, but I would be OK with the vbackup jobs
being a one-time consolidation without the ability to go back -- I would
use it to get to a "minimum number of tapes to restore" state every so

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