Re: [linux-lvm] Data deduplication in LVM?

[Les Mikesell <lesmikesell gmail com>]

Roy Sigurd Karlsbakk wrote:
> On 11. juni. 2009, at 00.30, Stuart D. Gathman wrote:
>
> > One OSS backup product that does
> > deduplication is BackupPC (written in Perl).  In the backup server, 
> > every file
> > gets hard linked to a name in a special directory that is its md5 
> > checksum
> > (plus some fiddly logic to handle metadata)
>
>
> This sounds like file-level deduplication. Most storage systems sing 
> dedup, uses block-level dedup. NetApp is one example; they dedup 
> everything with 4k blocks, doing the actual deduplication at night.

Yes, it is a different concept.  However it does work very well when you 
are storing your backups on a filesystem without block-level dedup.  And 
that is probably the place where you have the most redundancy - or if 
you don't already, you'll be able to store a much longer history.

--
  Les Mikesell
   lesmikesell gmail com