From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joshua West Subject: Re: Hypervisor Memory Limitations on 64-bit Architecture? Date: Fri, 18 Jul 2008 18:49:26 -0400 Message-ID: <48811DF6.2040309@brandeis.edu> References: <4880CB42.5010802@brandeis.edu> <20080718191008.GC3771@edu.joroinen.fi> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <20080718191008.GC3771@edu.joroinen.fi> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: =?ISO-8859-1?Q?Pasi_K=E4rkk=E4inen?= Cc: "xen-devel@lists.xensource.com" List-Id: xen-devel@lists.xenproject.org Hi Pasi, Thanks for the information. Do you have any details regarding x86_64 architecture memory limits with the Xen Hypervisor, using stock Xen -- instead of those modified/patched by vendors like Red Hat? Thanks. Pasi K=E4rkk=E4inen wrote: > On Fri, Jul 18, 2008 at 12:56:34PM -0400, Joshua West wrote: > =20 >> Hey all, >> >> I'm wondering if anybody could shed some light on this subject. Are >> there limitations as to how much RAM a 64-bit Hypervisor will >> recognize/support under the Xen 3.1.x or 3.2.x series (or the upcoming >> 3.3.x if anything has changed)? >> >> >From what I recall, a 32-bit Xen Hypervisor will recognize up to 16GB= of >> RAM and a 64-bit Xen Hypervisor will recognize up to 32GB -- but I'm n= ot >> certain on if 32GB is in fact the upper limit for 64-bit Xen. >> >> =20 > > http://www.redhat.com/rhel/compare/ > > RHEL5 supports 16 GB of mem on x86 (32bit) platform.=20 > RHEL5 supports 256 GB of mem on x86_64 platform. > > And RHEL5 contains Xen. > > http://www.nabble.com/Unable-to-start-hvm-guest-on-cs16998-td15419631.h= tml > > "Running Xen Unstable changeset 16998 (pulled 20080208) on Unisys ES70= 00/one 64x 256gb with SLE10SP1 x64." > > There you have an actual server with 256 GB of mem running Xen :)=20 > > (yeah, the mail is about problems, but hey, it's xen-unstable repositor= y > they're testing there :) > > -- Pasi > =20 --=20 Joshua West Systems Engineer Brandeis University http://www.brandeis.edu