On 01/27/11 07:33, Graham Keeling wrote:
> On Thu, Jan 27, 2011 at 06:26:04AM -0500, Phil Stracchino wrote:
>> On 01/27/11 06:12, Graham Keeling wrote:
>>> I think this last problem is what Phil is trying to solve by setting either
>>> Maximum Volume Jobs or Volume Use Duration. But these solutions seem
>>> unsatisfactory for disks (I can't comment on tapes because I don't know 
>>> enough
>>> about them).
>>> You are wasting space if the volume is not full up by the time Volume Use
>>> Duration expires.
>>
>> Define "full".  Disk volumes aren't like packing crates.  They're more
>> like balloons.  They grow as you add data to them.
> 
> The idea is to split the disk up into equal-sized chunks. 
> In this scenario, you have specified a number of volumes, and a maximum size
> for each volume. For example, on a terabyte disk, you might define 100 
> volumes,
> 10GB each.
> 
> If you don't use the "full" 10GB in each volume, the space that you don't use
> is wasted.

No, it isn't.  Because it isn't used.  If you set maximum volume size to
10GB, and you create a new volume and write a 5KB job to it, you have
5KB of data in a 5KB volume, not 5KB of data in a 10GB volume.

Now, if that volume fills, and gets purged, and you *keep the purged
volume around consuming 10GB of disk space* until it gets reused, well,
then you're wasting disk space, yes.  But that has absolutely nothing to
do with what's governing the size of the volume.  It is always going to
be the case with any purged disk volume.

5.0.3 has a feature to truncate purged disk volumes which gets around
this.  But the problem can equally easily be addressed by only using any
given volume once - by whatever means you decide it's "full" - deleting
used volumes as you purge them.

> You can't use the unused space for some other application, because the volume
> might get purged, recycled, and then the next job that writes to it wants to
> use all 10GB - you will then find that it can't.

This simply neither reflects reality nor makes any sense.  I can't even
understand what you're trying to say here.


-- 
  Phil Stracchino, CDK#2     DoD#299792458     ICBM: 43.5607, -71.355
  alaric AT caerllewys DOT net   alaric AT metrocast DOT net   phil AT 
co.ordinate DOT org
         Renaissance Man, Unix ronin, Perl hacker, Free Stater
                 It's not the years, it's the mileage.

------------------------------------------------------------------------------
Special Offer-- Download ArcSight Logger for FREE (a $49 USD value)!
Finally, a world-class log management solution at an even better price-free!
Download using promo code Free_Logger_4_Dev2Dev. Offer expires 
February 28th, so secure your free ArcSight Logger TODAY! 
http://p.sf.net/sfu/arcsight-sfd2d
_______________________________________________
Bacula-users mailing list
Bacula-users AT lists.sourceforge DOT net
https://lists.sourceforge.net/lists/listinfo/bacula-users