Re: [Bacula-users] How to organize File-Bases Volumes...

[Graham K. <gr...@eq...>]

On Thu, Jan 27, 2011 at 09:45:29AM -0500, Phil Stracchino wrote:
> On 01/27/11 09:28, Graham Keeling wrote:
> > I shall summarise what I thought I had already said, because it is quite clear
> > to me.
> > 
> > You have a terabyte disk that you want to use for backups.
> > 
> > You split it into 100 Volumes, set 10GB max volume size each, and 1 job
> > per volume.
> > 
> > All your backup jobs are 5KB.
> > You can then only use 500KB of disk space before you run out of volumes.
> 
> Assuming that you've also set max volumes = 100.
> 
> However, I believe in this case the problem is summarized by PEBCAK.  If
> all of your backup jobs are 5KB, this would be a completely
> brain-damaged way to set up your storage.

Please don't be deliberately obtuse.
The point of the example is to use an extreme to easily demonstrate real
problems.
I used the specific figure of 5KB to provide continuity with your own example
in which you used the same figure.


The same problems exist in more realistic situations.

Assuming that I somehow know that all my backups will range from 100MB to 10GB,
then what should I set?

a) 10000 volumes, 100MB max size?
b)   100 volumes,  10GB max size?

a) gives me wasted space when a backup is not a multiple of 100MB in size,
and possible overhead problems due to the number of volumes.
b) gives me wasted space when a backup is not a multiple of 10GB in size.