The minimum amount of memory needed to use ZFS.

[krad]

If you want something small and cheap you could look at a Celeron based
Intel nuc or similar.  I think I built mine for about £150, it has an ssd
and 4gb or ram and runs zfs on root fine. It's basically a beefy router
with inbuilt transparent web caching. It works well and is relatively low
power for what I need. The pi and aurdino would be in a different league
though in both senses of power
On 23 Dec 2015 17:58, "Bob Bishop" <rb at gid.co.uk> wrote:

> Hi,
>
> > On 23 Dec 2015, at 12:14, andrew clarke <mail at ozzmosis.com> wrote:
> >
> > On Wed 2015-12-23 21:43:37 UTC+1100, Stephen Hocking (
> stephen.hocking at gmail.com) wrote:
> >
> >> Inspired by this article:
> >>
> http://arstechnica.com/information-technology/2015/12/rsync-net-zfs-replication-to-the-cloud-is-finally-here-and-its-fast/
> >>
> >> I am wondering about changing my offsite back strategy, which currently
> is
> >> made up of a Raspberry Pi with an external 3TB drive sitting at my
> >> brother's house, with periodic manual rsyncs. I'd like to change that to
> >> doing zfs replications.
> >>
> >> I want to use some of my ARM based hardware as the target for the ZFS
> >> replication, owing to its low power usage. I have a few Cubiboxes
> floating
> >> around with around 2G of RAM, and a RPI2 or a Banana Pi with 1G. It'd
> have
> >> a UFS root on the SD card, and ZFS on the external drive.
> >>
> >> Any ideas?
> >
> > I'm curious about this too.
> >
> > Currently I run a root-on-ZFS FreeBSD 10.2 amd64 system with 2 GB RAM
> > that I use for offline backups. The ZFS pool consists of 2 x 1 TB
> > drives in a mirror setup. I've never had FreeBSD run out of memory on
> > that machine.
> >
> > I suggest you avoid using the deduplication feature of ZFS which from
> > what I understands likes to chew through memory.
> >
> > I don't use ZFS snapshots on that machine, so can't speak about their
> > memory usage. Perhaps it's fairly insignificant, though.
> >
> > An alternative might be to use something like rsnapshot, still on ZFS.
> >
> > You might get a bigger audience if you ask on the freebsd-questions
> > list.
> >
> > Regards
> > Andrew
>
> FWIW we have a backup box currently running 9.2 amd64 with 4GB RAM and a
> ZFS mirror. We use rsync to transfer the data daily, and ZFS snapshots to
> maintain a Time Machine-like structure (currently something over 150
> snapshots in play). We did have some instances of apparent memory
> exhaustion until we limited vfs.zfs.arc_max to 2GB; that doesn’t seem to
> have affected performance.
>
> Deduplication seems like a very bad idea unless you have both a lot of
> duplicated data and a serious shortage of disk. It needs a lot of RAM,
> increasing over time. Depending on the hardware and the use case,
> compression (which effectively only costs CPU) might be a better option.
>
> --
> Bob Bishop
> rb at gid.co.uk
>
>
>
>
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