From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Bareiro Subject: Re: KVM RAM limitation Date: Thu, 4 Feb 2010 14:47:13 -0300 Message-ID: <20100204174713.GJ6798@defiant.freesoftware> References: <20100203155541.GC6798@defiant.freesoftware> <4B69CC6C.2090506@codemonkey.ws> <20100203200653.GG6798@defiant.freesoftware> <201002031644.28348.iggy@theiggy.com> Reply-To: dbareiro@gmx.net Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="ijf6z65S790CMqo8" Cc: KVM General To: Brian Jackson Return-path: Received: from mail.gmx.net ([213.165.64.20]:35582 "HELO mail.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1754196Ab0BDRrZ (ORCPT ); Thu, 4 Feb 2010 12:47:25 -0500 Content-Disposition: inline In-Reply-To: <201002031644.28348.iggy@theiggy.com> Sender: kvm-owner@vger.kernel.org List-ID: --ijf6z65S790CMqo8 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi, Brian. On Wednesday, 03 February 2010 16:44:28 -0600, Brian Jackson wrote: > > Anthony Liguori wrote: > > >>> Are you sure you enabled KVM? Are you sure you are using the KVM > > >>> binary and not some QEMU binary that's sitting around. This is one > > >>> of those situations where the KVM command you are running might > > >>> help. Also the same binary you are running's version ($QEMU_BIN -h > > >>>=20 > > >>> | head -n1) > > >> wilson:/usr/local/qemu-kvm/bin# ./qemu-system-x86_64 -h | head -n1 > > >> QEMU PC emulator version 0.12.2 (qemu-kvm-0.12.2), Copyright (c) > > >> 2003-2008 Fabrice Bellard > > >>=20 > > >>=20 > > >> The procedure that I used to compile qemu-kvm is the same of always: > > >> to download qemu-kvm-0.12.2, to install the packages (Debian) > > >> zlib1g-dev and libpci-dev, and to compile of the following way: > > >>=20 > > >> # cd qemu-kvm-0.12.2 > > >> # ./configure --prefix=3D/usr/local/qemu-kvm > > >> # make > > >> # make install > > >>=20 > > >> Until the moment I never got to use qemu-kvm with VMs of more than > > >> 2048 MB. In an installation that I have with KVM-88 and kernel x86_64 > > >> I don't have this problem. > > > QEMU and KVM only support 2GB of memory on a 32-bit host. > > >=20 > > > Both need to create a userspace mapping of the guests memory. In a > > > 32-bit environment, you only have enough usable address space in a > > > process to create a 2GB region. =20 > > But, according to what I read in the link [1] that commented, just by to > > have a x86_64 kernel would have to be sufficient to serve more than 2047 > > MB of RAM. > The kvm userspace would also have to be compiled as a 64bit binary. > Possibly statically compiled somewhere else (if that's even possible) > or with a 64bit chroot. Hmmm... and there is some way to compile qemu-kvm as a 64bit binary on a operating system userspace of 32bit? I tried with ARCH=3Dx86_64 with make but when using this I obtain several messages of the type "cast to/from pointer from/to integer of different size". Thanks for your reply. Regards, Daniel --=20 Mi frase del d=EDa: An algorithm must be seen to be believed. -- D. E. Knuth Daniel Bareiro - GNU/Linux registered user #188.598 Proudly running Debian GNU/Linux with uptime: 14:02:40 up 31 days, 22:47, 11 users, load average: 0.00, 0.02, 0.00 --ijf6z65S790CMqo8 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (GNU/Linux) iEYEARECAAYFAktrCCEACgkQZpa/GxTmHTfMpwCfeVtlHFeROO/xY6CW8QNDQJDJ /HgAn28OX43iI7dyUmotGhq3WVKkbcp9 =ZbET -----END PGP SIGNATURE----- --ijf6z65S790CMqo8--