[Discuss] Backing up the entire filesystem

[Dan Ritter]

On Fri, Oct 26, 2018 at 02:18:12PM -0400, Shirley Márquez Dúlcey wrote:
> My NAS boxes each have 16GB. One has two 4TB and two 3TB drives in
> mirrored pairs; the other has three 1.5TB drives in a RAIDZ1 setup.
> And that's just for being a NAS. I would probably need more RAM,
> especially on the one with four drives, if I were also running
> applications on them.
> 
> Why two smaller boxes rather than one big one? Mostly because I
> already own a pair of low end AMD systems using mini-ITX motherboards
> and AM1 socket CPUs that I originally got for another purpose but was
> no longer using, and I already had all the drives. Those motherboards
> only have two DDR3 memory sockets and thus have a RAM ceiling of 16GB,
> and the cases will only hold four hard drives.
> On Fri, Oct 26, 2018 at 2:04 PM Marco Milano <marco.milano at gmx.com> wrote:
> >
> >
> >
> > On 10/26/18 1:55 PM, Shirley Márquez Dúlcey wrote:
> > > Another thing to keep in mind is that ZFS does have one flaw; it's a
> > > memory hog. If you have a large ZFS filesystem you will need a LOT of
> > > RAM to get acceptable performance. But it does represent the current
> > > state of the art for file system data integrity.
> >
> > I think as long as you don't use dedup, it works perfectly fine
> > on a system with 8GB or 16GB RAM.

The rule of thumb is 1GB per TB of used space, so for Shirley's
NAS boxes, dedup would actually work. I don't recommend it,
though.

-dsr-