Re: [ovirt-users] Mixing CPU types

From: "Matthew Trent" <Matthew.Trent(a)lewiscountywa.gov&gt; To: "Yaniv Kaul" <ykaul(a)redhat.com&gt; Cc: users(a)ovirt.org Sent: Wednesday, February 3, 2016 8:10:35 PM Subject: Re: [ovirt-users] Mixing CPU types ?Actually it works great! It's been supported by KVM for a while now. I had one Proxmox cluster with a mix of AMD and Intel and migrated KVM VM's between them frequently. OpenStack (KVM) and VMWare support this as well. The trick is to expose a virtual CPU with a common set of features to the VMs. KVM handles the rest. From the KVM FAQ: http://www.linux-kvm.org/page/FAQ#Does_KVM_support_live_migration_from_an...

"Does KVM support live migration from an AMD host to an Intel host and back? Yes. There may be issues on 32-bit Intel hosts which don't support NX (or XD), but for 64-bit hosts back and forth migration should work well. Migration of 32-bit guests should work between 32-bit hosts and 64-bit hosts. If one of your hosts does not support NX, you may consider disabling NX when starting the guest on a NX-capable system. You can do it by passing "-cpu qemu64,-nx" parameter to the guest." -- Matthew Trent Network Engineer Lewis County IT Services 360.740.1247 - Helpdesk 360.740.3343 - Direct line ________________________________ From: Yaniv Kaul <ykaul(a)redhat.com&gt; Sent: Tuesday, February 2, 2016 2:17 PM To: Matthew Trent Cc: users(a)ovirt.org Subject: Re: [ovirt-users] Mixing CPU types On Mon, Feb 1, 2016 at 9:13 PM, Matthew Trent <Matthew.Trent@lewiscountywa.gov<mailto:Matthew.Trent@lewiscountywa.gov>> wrote: Though our new oVirt setup is better in most ways, cross-CPU-type migration is one of the features I miss from Proxmox. KVM supports mixed-CPU migration for a while now, even between AMD and Intel. http://www.linux-kvm.org/page/Migration I highly doubt the above works in real life scenarios. Y. I'm using a bunch of re-purposed servers with a mix of AMD and Intel. I separate them into clusters, as noted, but it sure would be nice to be able to live migrate between them. :) -- Matthew Trent Network Engineer Lewis County IT Services > Hi Rene, > > Thank you very much for coming back to me. > > That's perfect then and answers my questions exactly. > > Much appreciated. > > Regards. > >Neil Wilson. > > >On Wed, Jan 27, 2016 at 1:57 PM, René Koch <rkoch at >rk-it.at<http://rk-it.at>> wrote: >> >> Hi Neil, >> >> You can mix cpu types (but not AMD and Intel) if you leave the cluster >> level at the lowest cpu level. >> I personally don't mix cpu levels if possible, but instead create own >> clusters for each cpu type in order to be able to use the newest cpu >> features... >> >> >> Regards, >> René >> >> >> On 01/27/2016 12:53 PM, Neil wrote: >> >> Hi guys, >> >> I currently have an oVirt 3.5 cluster with Sandy Bridge Xeon CPU's, and I >> need to add a new host for more RAM and vCPU's, however the new Xeon e5 >> cpu's are Haswell based. >> >> Can I mix CPU types (Haswell and Sandy Bridge) in my cluster and will I be >> able to migrate between my hosts? >> >> I'm guessing that for this to work I'll need to leave my "CPU type" set to >> Sandy Bridge, will the Haswell based CPU be compatible with my cluster, >> but >> just run without any Haswell type features? >> >> Apologies if this is a dumb question or if it's been answered before. >> >> Thank you. >> >> Regards. >> >> Neil Wilson >> _______________________________________________ Users mailing list Users@ovirt.org<mailto:Users@ovirt.org> http://lists.ovirt.org/mailman/listinfo/users _______________________________________________ Users mailing list Users(a)ovirt.org http://lists.ovirt.org/mailman/listinfo/users