continuous backup solution for FreeBSD

[Zaphod Beeblebrox]

On Tue, Oct 7, 2008 at 11:50 AM, Shaun Amott <shaun at freebsd.org> wrote:

> On Tue, Oct 07, 2008 at 12:31:58AM +0300, Evren Yurtesen wrote:
> >
> > so FreeBSD could be supported also. As you can imagine, it is not only
> > important that data can be restored when a box hardware failure etc. it
> is
> > also important that data can be restored if deleted by accidents etc.
> While
> > traditional backup programs provide this functionality, you cant really
> go
> > back to 10 min or 1h ago, often they take daily backups and have to scan
> > whole filesystem for changed files every time the backup is taken which
> > stresses out the systems.
> >
>
> This can (more or less) be achieved with snapshots: you can cheaply
> maintain old versions of the file system, and mount an old snapshot at
> any time. Hourly is about as fine-grained as you can expect though.
>

Unfortunately, as mentioned on another recent thread, FreeBSD UFS snapshots
are quite fragile.  The last time I tried this type-of-thing, it rather
quickly resulted in filesystem corruption on moderately busy filesystems.
Also, the cost of UFS snapshots (in time, while locking the filesystem) are
unacceptable in practice.

Now... ZFS seems to do this well enough.  I use snapshots and send snapshots
to my backup server --- it all seems to work OK.

The idea that snapshots have infinite granularity and are automatic
(introduced to me by the Hammer filesystem document) has merit, though ---
and this is certainly core to the featurelist of the company that started
this thread
.