Re: Homebuilt NAS Advice
On Fri, 7 Aug 2020 18:02:11 -0400
rhkramer@gmail.com wrote:
> On Friday, August 07, 2020 01:36:21 PM Celejar wrote:
> > On Fri, 7 Aug 2020 17:21:44 +0100
> >
> > Jonathan Dowland <jon+debian-user@dow.land> wrote:
> > > On Thu, Aug 06, 2020 at 12:03:56PM -0400, Celejar wrote:
> > > >Ah, okay. So IIUC, each time you backup you do a full backup, and you
> > > >then convert the previous backups into the reverse of the more common
> > > >incremental / differential backups.
> > >
> > > It's an implementation detail: rdiff-backup does it too, I suspect it's
> > > commonly done. From what I recall many version control systems do
> > > something similar.
> >
> > Thanks. But what's the advantage? Isn't it more work on each backup (of
> > which there are typically many), in exchange for less work on restores
> > (which are typically quite rare)? What am I missing?
>
> Ok, I went back and did a little research. RCS, one of the early version
> control systems, used reverse deltas for the main line of development --
> forward deltas for branches, it's a long story ;-).
>
> The intent of the reverse deltas in RCS (according to the Tichy paper) was
> (is) to allow fast checkout of the most recent version.
Fair enough. But less applicable in the case of backups, since restores
are quite rare, as I've been pointing out.
> [[https://docs.lib.purdue.edu/cgi/viewcontent.cgi?article=1393&context=cstech]
> [RCS: A System for Version Control - Purdue e-Pubs]]
Celejar
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