From owner-freebsd-stable@freebsd.org Fri Jul 24 00:54:06 2015 Return-Path: Delivered-To: freebsd-stable@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 8941D9A9CBC for ; Fri, 24 Jul 2015 00:54:06 +0000 (UTC) (envelope-from michelle@sorbs.net) Received: from hades.sorbs.net (hades.sorbs.net [67.231.146.201]) by mx1.freebsd.org (Postfix) with ESMTP id 7657718D5; Fri, 24 Jul 2015 00:54:06 +0000 (UTC) (envelope-from michelle@sorbs.net) MIME-version: 1.0 Content-transfer-encoding: 7BIT Content-type: text/plain; CHARSET=US-ASCII Received: from isux.com (firewall.isux.com [213.165.190.213]) by hades.sorbs.net (Oracle Communications Messaging Server 7.0.5.29.0 64bit (built Jul 9 2013)) with ESMTPSA id <0NRY00I53W3YGN00@hades.sorbs.net>; Thu, 23 Jul 2015 18:00:01 -0700 (PDT) Message-id: <55B18CA8.1020909@sorbs.net> Date: Fri, 24 Jul 2015 02:54:00 +0200 From: Michelle Sullivan User-Agent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X; en-US; rv:1.8.1.24) Gecko/20100301 SeaMonkey/1.1.19 To: Glen Barber Cc: Mark Linimon , Brandon Allbery , freebsd-stable , Jason Unovitch , herbert@oslo.ath.cx Subject: Re: 10.2-Beta i386..what's wrong..? References: <55B17B7A.4080402@gmail.com> <20150723234805.GK84931@FreeBSD.org> <55B18488.9060602@sorbs.net> <20150724004026.GA1370@lonesome.com> <20150724004343.GM84931@FreeBSD.org> <20150724004443.GC1370@lonesome.com> <20150724004939.GN84931@FreeBSD.org> In-reply-to: <20150724004939.GN84931@FreeBSD.org> X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 24 Jul 2015 00:54:06 -0000 Glen Barber wrote: > On Thu, Jul 23, 2015 at 07:44:43PM -0500, Mark Linimon wrote: > >> On Fri, Jul 24, 2015 at 12:43:43AM +0000, Glen Barber wrote: >> >>> Even on amd64, you need to tune the system with less than 4GB RAM. >>> >> The only correct answer to "how much RAM do you need to run ZFS" is >> "always more" AFAICT. >> >> > > 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 > > 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... -- Michelle Sullivan http://www.mhix.org/