Re: Homebuilt NAS Advice
On Thu, 6 Aug 2020 05:02:17 -0500
Leslie Rhorer <lesrhorer@att.net> wrote:
> On 8/5/2020 9:11 AM, Stefan Monnier wrote:
> >> I prefer DAR for several reasons. First of all, as I mentioned
> >> before, DAR is the only backup solution of which I am aware that can
> >> restore not only deleted or corrupted files, but which can also
> >> restore deletions. This means DAR can restore any or all files one
> >> chooses in a batch, but then if requested can go back and delete
> >> files which were deleted at a later time but prior to additional
> >> DAR backups.
> >
> > I find it hard to believe that it's a rare feature.
> >
> > The system I use (`bup`) does support that as well (every backup is
> > (more or less) a Git commit, so it doesn't distinguish full-backups from
> > incrementals), but it doesn't bother to mention it probably because it's
> > very basic.
>
> Uh-uh. Full, incremenal, and decremental backups are all completely
> different than deletion restoral. A GIT commit is somewhat similar, as
> is a VM snapshot, but they also are not quite the same.
>
> All I can say is, "I suggest you read all the features - it is quite a
> long list - and try it."
I (and I suspect others here) are still pretty confused about what you
are trying to explain to us. Here's what I do, and do not, understand:
* Incremental and differential backups are backups of the delta between
the last full backup and the current system state (either individually
[differential] or collectively [incremental])
* I have no idea (nor do Google, DuckDuckGo, or Wikipedia) what a
"decremental backup" is.
* Borg doesn't fit the "full / differential / incremental" paradigm
neatly, but it certainly has some of the advantages of differential /
incremental backups (plus others that classic differential /
incremental ones do not have, such as deduplication - i.e., if the
backup source contains multiple copies of some data, that dataonly
needs to be stored once in the backup target).
* I don't know exactly what you mean by "deletion restoral", but Borg
(and, I assume, many other good backup solutions) offers a
flexible variety of methods to restore deleted files, and / or to
restore a snapshot of the backup source as it existed at a given point
in time: https://docs.borgbase.com/restore/
If you are willing to explain further, that would be appreciated.
Thanks!
Celejar
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