From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:56272) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZKMvH-0005n3-Mb for qemu-devel@nongnu.org; Wed, 29 Jul 2015 04:41:13 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZKMvE-00032v-CT for qemu-devel@nongnu.org; Wed, 29 Jul 2015 04:41:11 -0400 Received: from mail-wi0-f172.google.com ([209.85.212.172]:36481) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZKMvE-00032f-3o for qemu-devel@nongnu.org; Wed, 29 Jul 2015 04:41:08 -0400 Received: by wicgb10 with SMTP id gb10so189739637wic.1 for ; Wed, 29 Jul 2015 01:41:07 -0700 (PDT) Date: Wed, 29 Jul 2015 10:41:05 +0200 From: Eduardo Otubo Message-ID: <20150729084104.GB7667@vader> References: <20150728132213.GA1603@vader> <20150728151946.GF2247@work-vm> <20150729080303.GA7667@vader> <20150729081121.GA2267@work-vm> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="cvVnyQ+4j833TQvp" Content-Disposition: inline In-Reply-To: <20150729081121.GA2267@work-vm> Subject: Re: [Qemu-devel] Live migration hangs after migration to remote host List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Dr. David Alan Gilbert" Cc: Qemu-devel --cvVnyQ+4j833TQvp Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Jul 29, 2015 at 09=3D11=3D21AM +0100, Dr. David Alan Gilbert wrote: > * Eduardo Otubo (eduardo.otubo@profitbricks.com) wrote: > > On Tue, Jul 28, 2015 at 04=3D19=3D46PM +0100, Dr. David Alan Gilbert wr= ote: > > > * Eduardo Otubo (eduardo.otubo@profitbricks.com) wrote: > > > > Hello all, > > > >=20 > > > > I'm facing a weird behavior on my tests: I am able to live migrate > > > > between two virtual machines on my localhost, but not to another > > > > machine, both using tcp. > > > >=20 > > > > * I am using the same arguments on the command line; > > > > * Both virtual machines uses the same qcow2 file visible through NF= S; > > > > * Both machines are in the same subnet; > > > > * Migration is being done from intel to intel; > > > > * Same version of Qemu (github master - f8787f8723); > > > >=20 > > > > Using all above I am able to live migrate on the same host: between= two > > > > vms on local host or between two vms in the remote host; but when > > > > migrating from local to remote, the guest hangs. I still can access= its > > > > console via ctrl+alt+2, though, and everything seems to be normal. = If I > > > > issue a reboote via console on the remote, the guest gets back to > > > > normal. > > > >=20 > > > > Am I missing something here? > > >=20 > > > Just checking, but are you saying that as far as qemu is concerned, t= he migration > > > is happy, it's just the guest that's hung? > >=20 > > That's exactly the case. The console (via ctrl+alt+2) is active and > > responding to all commands normally, but the screen (ctrl+alt+1) is > > frozen and I can't interact with it at all. >=20 > Are you driving this via libvirt or using qemu monitor directly? > If the latter, can you please get an 'info migrate' from the source > and an 'info status' from the destination at the end of migrate. I'm using qemu command line directly. And I got the problem :) See below. >=20 > > > Are the host clocks on the two hosts very close (there are lots of > > > weird corner cases with mismatched clocks) - same time zone? > >=20 > > Yep. Both machines are in the same room and have the clock sync'ed. >=20 > OK, good. >=20 > > >=20 > > > Are you using cache=3Dnone (given that it's NFS shared) > >=20 > > I wasn't. But I tried again with cache=3Dnone and I got exactly the same > > thing. >=20 > OK, and this pair of machines, have you tried both directions - i.e. > going a->b and b->a - do both directions fail? > Is the NFS server one of the two machines? If it is, and you're using li= bvirt, > make sure that the directory the disks are on is an NFS mount on both > machines; e.g. don't migrate directly from the NFS export. >=20 > > Also, I tried with stable-2.2 branch and got the same behavior. I really > > think that's very unlikely to have unstable code of such an important > > feature upstream, or on a stable- branch. Most probable thing is that > > I have something wrong on my environment. >=20 > Yes, the challenge is to find what; and if it's something common > we should try and find a way of spotting it. >=20 > > Anyway, I'll keep tetsing different stable- branches until I find > > something that works for me. I'll keep the mailing list posted. >=20 > Could you share the qemu command line so we can see if we can > spot anything? Got the problem! I tried to simplify my qemu command line to the smallest possible, excluding things I thought it could cause the issue. With no further due, this is the argument: -cpu 'Opteron_G4' Without this argument everything works as it should, console responsive and guest active :) It says on the documentation[1] that it's possible to migrate between AMD and Intel, but I think I got a corner case. Apparently I can't specify the exact CPU model. Is this a known issue? Couldn't find any reference on bugzilla or launchpad. [1] - http://www.linux-kvm.org/page/Migration --=20 Eduardo Otubo ProfitBricks GmbH --cvVnyQ+4j833TQvp Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQEcBAEBAgAGBQJVuJGgAAoJEP0M/1sS+L0vyskH/R1R57dBkcyyT01512fUEIx4 U7eGM2zJ+bcks+PSpg+CXCn9BYQGUiXkcqprTG92InZ5rtN3AQ8fwvomBkJTxVD8 iqoFF7547tTQvO6S89Du3tBWVEwEpp31xpPKpRjTtutW7DvdmArU4iDpafEe7iwN za/SJ7tbFGYzaxIGMnuXy9+c+ifjv6o8BSi0M1hUVJftS3nEdfV7LNGdTipePpJn PGXl6COEVyIhqYmIu1bBR3LGYw9Us66zg/OSKzzOvhjImVn1frbI1CMa/ltidbJs GZxl+6QQp7iD/DsCWpoRPir0G+zNLYKaJbRjvh8wcg9seI4dBwq+bs0Vk8ThGO4= =873B -----END PGP SIGNATURE----- --cvVnyQ+4j833TQvp--