Real World DragonFlyBSD Hammer DeDup figures from HiFX - Reclaiming more than 1/4th ( 30% ) Disk Space from an Almost Full Drive

[Steve O'Hara-Smith]

On Thu, 21 Jul 2011 09:56:38 +0200
"Sascha Wildner" <saw at online.de> wrote:

> On Thu, 21 Jul 2011 06:23:16 +0200, Siju George <sgeorge.ml at gmail.com>  
> wrote:
> 
> > On Thu, Jul 21, 2011 at 7:18 AM, Thomas Keusch
> > <fwd+usenet-spam2011q3 at bsd-solutions-duesseldorf.de> wrote:
> >>
> >> nice statistics. I can not provide stats of my own, as I don't run
> >> Dragonfly yet, so I'm more of a hypothetical user right now. But one
> >> thing that's of interest to me is how long did the de-dupe process
> >> take?
> >>
> >
> > I ran them one by one. at my own pace but the biggest two
> > simultaneously did not take more than 2 hrs.
> > So I guess 2-3 hrs would be a nice approximation :-)
> 
> My experiences were different on a file system containing a lot of data  
> (>2TB).
> 
> I didn't try dedup itself but a dedup-simulate already ran for more than  
> two days (consuming a lot of memory in the process) before I finally  
> cancelled it.

	Most odd - I just tried a dedup-simulate on a 2TB filesystem with
about 840GB used, it finished in about 30 seconds and reported a ratio of
1.01 (dedup has been running automatically every night on this FS).

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