Re: [Duplicity-talk] Minimizing risk on incremental

[arie]

On Sat, 22 Apr 2017 11:39:24 -0700
Mark Grandi via Duplicity-talk <address@hidden> wrote:

> You can use the par2 wrapper backend that takes a little more space
> but provides redundancy if one of the chain files gets corrupted
> somehow (flips a bit...Solar radiation? Bad disk?)

I'm interested in this wrapper but can't find a reference to it.
My version is 0.6.22

harry


> ~mark
> 
> On Apr 22, 2017 6:15 AM, "Manuel Morales via Duplicity-talk" <
> address@hidden> wrote:
> 
> > As written on Wikipedia, about Duplicity:
> >
> > “Chains consisting of a full backup and a series of incremental
> > backups can be recovered to the point in time that any of the
> > incremental steps were taken. If any of the incremental backups are
> > missing then the incremental backups following it cannot be
> > reconstructed.”
> >
> >
> >
> > Im concerned about those chains, in my particular implementation.
> >
> > Im using rsync.net as backend, and they automatically create a daily
> > snapshot of whatever we put there.
> >
> > Each snapshot is a “picture of the file system” as it existed when
> > was taken.
> >
> >
> >
> > If I just do simple rsync to rsync.net, only the changes are
> > transmitted, but the filesystem is a “copy” of the source, not an
> > “incremental backup chain”
> >
> > Therefore, the rsync.net’s daily snapshot have only the changes, and
> > grows by the size of the data changed every day, letting me recover
> > any snapshot at any time, even if the snapshots in between are
> > lost/deleted.
> >
> >
> >
> > If I use Duplicity, I will be sending incremental every day, and if
> > one of those days is missing or corrupted, all my snapshots are
> > worthless, right?
> >
> > For example, lets say I have 400 GB of original data, and 2 GB of
> > changes per day.
> >
> >
> >
> > Day 1: Duplicity, first backup, totaling 400 GB (full)
> >
> > Day 1: rsync.net snapshot (full is recoverable)
> >
> > Day 2: Duplicity, incremental, totaling 2 GB (incremental)
> >
> > Day 2: rsync.net snapshot (full is recoverable, incremental might be
> > broken)
> >
> > Day 3: Duplicity, incremental, totaling 2 GB (incremental)
> >
> > Day 2: rsync.net snapshot (full is recoverable, incremental might be
> > broken because Day 2 is broken/missing)
> >
> > Etc
> >
> >
> >
> > If I continue forever, then I might be on day 200 and be able to
> > recovery only full back up from Day1.
> >
> > What am I missing here?
> >
> >
> >
> > I guess I could do full backup, every week, but that will cause a
> > full 400GB of data every week, so in few weeks I will have a few
> > Terabytes of data on rsync.net.
> >
> >
> >
> > Is there any way to make duplicity just sync the file system, and
> > avoid the incremental part?
> >
> > The attractive part of duplicity in my case is the encryption, but
> > it seems the “incremental backup” is not ideal for me.
> >
> >
> >
> > Thoughts?
> >
> > Thanks!
> >
> > Dotty
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> > _______________________________________________
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> > https://lists.nongnu.org/mailman/listinfo/duplicity-talk
> >
> >