Skip site navigation (1)Skip section navigation (2)
Date:      Fri, 24 Jul 2015 01:00:03 +0000
From:      Glen Barber <gjb@FreeBSD.org>
To:        Michelle Sullivan <michelle@sorbs.net>
Cc:        Mark Linimon <linimon@lonesome.com>, Brandon Allbery <allbery.b@gmail.com>, freebsd-stable <freebsd-stable@freebsd.org>, Jason Unovitch <jason.unovitch@gmail.com>, herbert@oslo.ath.cx
Subject:   Re: 10.2-Beta i386..what's wrong..?
Message-ID:  <20150724010003.GO84931@FreeBSD.org>
In-Reply-To: <55B18CA8.1020909@sorbs.net>
References:  <55B17B7A.4080402@gmail.com> <20150723234805.GK84931@FreeBSD.org> <55B18488.9060602@sorbs.net> <20150724004026.GA1370@lonesome.com> <CAKFCL4VVtLspj%2BRQxSHjyQxAhixPuMiQoehoA2MYWeSgqTTwAQ@mail.gmail.com> <20150724004343.GM84931@FreeBSD.org> <20150724004443.GC1370@lonesome.com> <20150724004939.GN84931@FreeBSD.org> <55B18CA8.1020909@sorbs.net>

next in thread | previous in thread | raw e-mail | index | archive | help

--V7BlxAaPrdhzdIM1
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable

On Fri, Jul 24, 2015 at 02:54:00AM +0200, Michelle Sullivan wrote:
> Glen Barber wrote:
> > On Thu, Jul 23, 2015 at 07:44:43PM -0500, Mark Linimon wrote:
> >  =20
> >> On Fri, Jul 24, 2015 at 12:43:43AM +0000, Glen Barber wrote:
> >>    =20
> >>> Even on amd64, you need to tune the system with less than 4GB RAM.
> >>>      =20
> >> The only correct answer to "how much RAM do you need to run ZFS" is
> >> "always more" AFAICT.
> >>
> >>    =20
> >
> > There's a bit more to it than that.  You *can* successfully run amd64
> > ZFS system with certain tunings (vfs.kmem_max IIRC), but you also need
> > to adjust things like disabling prefetching with less than 4GB RAM
> > (accessible to the OS).
> >
> > So yeah, "more RAM" is always a thing in this playing field.
> >
> > Glen
> >
> >  =20
> Actually I'm quite sucessfully running zfs on i386 (in a VM) ... here's
> the trick (which leads me to suspect ARC handling as the problem) - when
> I get to 512M of kernel space or less than 1G of RAM available system
> wide, I export/import the zfs pool...  Using this formula I have uptimes
> of months... I haven't yet tried the 'ARC patch' that was proposed
> recently...
>=20

Which FreeBSD version is this?  Things changed since 10.1-RELEASE and
what will be 10.2-RELEASE enough that I can't even get a single-disk ZFS
system (in VirtualBox) to boot on i386.  During 10.1-RELEASE testing,
I only saw problems with multi-disk setup (mirror, raidzN), but the
FreeBSD kernel grew since 10.1-RELEASE, so this is not unexpected.

Glen


--V7BlxAaPrdhzdIM1
Content-Type: application/pgp-signature

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2
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=O5A2
-----END PGP SIGNATURE-----

--V7BlxAaPrdhzdIM1--



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20150724010003.GO84931>