Re: [ovirt-users] Mixing CPU types
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'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> 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
On Mon, Feb 1, 2016 at 9:13 PM, Matthew Trent < 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.
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> 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 http://lists.ovirt.org/mailman/listinfo/users
--_000_1454526635762956lewiscountywagov_ Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable ?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 betw= een 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 V= Ms. KVM handles the rest. From the KVM FAQ: http://www.linux-kvm.org/page/FAQ#Does_KVM_support_live_migration_from_an_A= MD_host_to_an_Intel_host_and_back.3F "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 X= D), but for 64-bit hosts back and forth migration should work well. Migrati= on of 32-bit guests should work between 32-bit hosts and 64-bit hosts. If o= ne of your hosts does not support NX, you may consider disabling NX when st= arting the guest on a NX-capable system. You can do it by passing "-cpu qem= u64,-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@redhat.com> Sent: Tuesday, February 2, 2016 2:17 PM To: Matthew Trent Cc: users@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 migrati= on 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 sep= arate 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, Ren=E9 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, Ren=E9
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 --_000_1454526635762956lewiscountywagov_ Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable <html> <head> <meta http-equiv=3D"Content-Type" content=3D"text/html; charset=3Diso-8859-= 1"> <style type=3D"text/css" style=3D"display:none"><!-- p { margin-top: 0px; m= argin-bottom: 0px; }--></style> </head> <body dir=3D"ltr" style=3D"font-size:12pt;color:#000000;background-color:#F= FFFFF;font-family:Calibri,Arial,Helvetica,sans-serif;"> <p>Actually it works great! It's been supported by KVM for a wh= ile now. I had one Proxmox cluster with a mix of AMD and Intel and mig= rated KVM VM's between them frequently. OpenStack (KVM) and VMWar= e support this as well.<br> </p> <p><br> </p> <p>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:<br> </p> <p><a href=3D"http://www.linux-kvm.org/page/FAQ#Does_KVM_support_live_migra= tion_from_an_AMD_host_to_an_Intel_host_and_back.3F">http://www.linux-kvm.or= g/page/FAQ#Does_KVM_support_live_migration_from_an_AMD_host_to_an_Intel_hos= t_and_back.3F</a><br> </p> <p><br> </p> <p>"<span style=3D"font-size: 12pt;">Does KVM support live migration f= rom an AMD host to an Intel host and back?</span></p> <p><span style=3D"font-size: 12pt;"><br> </span></p> Yes. There may be issues on 32-bit Intel hosts which don't support NX (or X= D), but for 64-bit hosts back and forth migration should work well. Migrati= on of 32-bit guests should work between 32-bit hosts and 64-bit hosts. If o= ne 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 t= he guest." <div id=3D"Signature"> <div name=3D"divtagdefaultwrapper" style=3D"font-family:Calibri,Arial,Helve= tica,sans-serif; font-size:; margin:0"> <div class=3D"BodyFragment"><font size=3D"2"> <div class=3D"PlainText"><br> </div> <div class=3D"PlainText">--<br> Matthew Trent</div> <div class=3D"PlainText">Network Engineer<br> Lewis County IT Services</div> <div class=3D"PlainText">360.740.1247 - Helpdesk<br> 360.740.3343 - Direct line</div> </font></div> </div> </div> <div style=3D"color: rgb(33, 33, 33);"> <hr tabindex=3D"-1" style=3D"display:inline-block; width:98%"> <div id=3D"divRplyFwdMsg" dir=3D"ltr"><font face=3D"Calibri, sans-serif" co= lor=3D"#000000" style=3D"font-size:11pt"><b>From:</b> Yaniv Kaul <ykaul@= redhat.com><br> <b>Sent:</b> Tuesday, February 2, 2016 2:17 PM<br> <b>To:</b> Matthew Trent<br> <b>Cc:</b> users@ovirt.org<br> <b>Subject:</b> Re: [ovirt-users] Mixing CPU types</font> <div> </div> </div> <div> <div dir=3D"ltr"><br> <div class=3D"gmail_extra"><br> <div class=3D"gmail_quote">On Mon, Feb 1, 2016 at 9:13 PM, Matthew Trent <s= pan dir=3D"ltr"> <<a href=3D"mailto:Matthew.Trent@lewiscountywa.gov" target=3D"_blank">Ma= tthew.Trent@lewiscountywa.gov</a>></span> wrote:<br> <blockquote class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex; border-left:1= px #ccc solid; padding-left:1ex"> 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 migrati= on for a while now, even between AMD and Intel.<br> <br> <a href=3D"http://www.linux-kvm.org/page/Migration" rel=3D"noreferrer" targ= et=3D"_blank">http://www.linux-kvm.org/page/Migration</a></blockquote> <div><br> </div> <div>I highly doubt the above works in real life scenarios. </div> <div>Y.<br> </div> <div><br> </div> <blockquote class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex; border-left:1= px #ccc solid; padding-left:1ex"> <br> <br> I'm using a bunch of re-purposed servers with a mix of AMD and Intel. I sep= arate them into clusters, as noted, but it sure would be nice to be able to= live migrate between them. :)<br> <br> --<br> Matthew Trent<br> Network Engineer<br> Lewis County IT Services<br> <span class=3D"im HOEnZb"><br> > Hi Rene,<br> ><br> > Thank you very much for coming back to me.<br> ><br> > That's perfect then and answers my questions exactly.<br> ><br> > Much appreciated.<br> ><br> > Regards.<br> ><br> >Neil Wilson.<br> ><br> ><br> </span> <div class=3D"HOEnZb"> <div class=3D"h5">>On Wed, Jan 27, 2016 at 1:57 PM, Ren=E9 Koch <rkoc= h at <a href=3D"http://rk-it.at" rel=3D"noreferrer" target=3D"_blank"> rk-it.at</a>> wrote:<br> >><br> >> Hi Neil,<br> >><br> >> You can mix cpu types (but not AMD and Intel) if you leave the clu= ster<br> >> level at the lowest cpu level.<br> >> I personally don't mix cpu levels if possible, but instead create = own<br> >> clusters for each cpu type in order to be able to use the newest c= pu<br> >> features...<br> >><br> >><br> >> Regards,<br> >> Ren=E9<br> >><br> >><br> >> On 01/27/2016 12:53 PM, Neil wrote:<br> >><br> >> Hi guys,<br> >><br> >> I currently have an oVirt 3.5 cluster with Sandy Bridge Xeon CPU's= , and I<br> >> need to add a new host for more RAM and vCPU's, however the new Xe= on e5<br> >> cpu's are Haswell based.<br> >><br> >> Can I mix CPU types (Haswell and Sandy Bridge) in my cluster and w= ill I be<br> >> able to migrate between my hosts?<br> >><br> >> I'm guessing that for this to work I'll need to leave my "CPU= type" set to<br> >> Sandy Bridge, will the Haswell based CPU be compatible with my clu= ster, but<br> >> just run without any Haswell type features?<br> >><br> >> Apologies if this is a dumb question or if it's been answered befo= re.<br> >><br> >> Thank you.<br> >><br> >> Regards.<br> >><br> >> Neil Wilson<br> >><br> _______________________________________________<br> Users mailing list<br> <a href=3D"mailto:Users@ovirt.org">Users@ovirt.org</a><br> <a href=3D"http://lists.ovirt.org/mailman/listinfo/users" rel=3D"noreferrer= " target=3D"_blank">http://lists.ovirt.org/mailman/listinfo/users</a><br> <br> <br> </div> </div> </blockquote> </div> <br> </div> </div> </div> </div> </body> </html> --_000_1454526635762956lewiscountywagov_--
----- Original Message -----
From: "Matthew Trent" <Matthew.Trent@lewiscountywa.gov> To: "Yaniv Kaul" <ykaul@redhat.com> Cc: users@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_AM...
That is pretty much what libvirt does. The sandy-bridge, haswell and other cpu's that we expose are not really a CPUs, but sets of flags (called baseline CPUs in libvirt's terminology). Afaik there should be no issue running cluster with both CPU vendors, the problem is lack of testing on devel side as we mostly run single vendor clusters everywhere.
"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@redhat.com> Sent: Tuesday, February 2, 2016 2:17 PM To: Matthew Trent Cc: users@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@ovirt.org http://lists.ovirt.org/mailman/listinfo/users
Sure would be a nice feature, though! It would simplify things for those of us who build out of re-purposed Windows servers (still a lot of life left in them for Linux applications!) and end up with a mix of CPUs. For most of my VMs I don't need the latest and greatest CPU features, but being able to consolidate my hosts into fewer clusters would be really useful. Like you said, oVirt already allows mixing CPU generations by selecting the lowest common denominator CPU type -- as long as you stick to Intel or AMD. It's a similar scenario, and the KVM stuff seems well established. Just expose some additional "generic" CPU types, per the KVM docs, and allow mixed clusters... -- Matthew Trent Network Engineer Lewis County IT Services 360.740.1247 - Helpdesk 360.740.3343 - Direct line ________________________________________ From: Martin Polednik <mpolednik@redhat.com> Sent: Wednesday, February 3, 2016 11:43 PM To: Matthew Trent Cc: Yaniv Kaul; users@ovirt.org Subject: Re: [ovirt-users] Mixing CPU types ----- Original Message -----
From: "Matthew Trent" <Matthew.Trent@lewiscountywa.gov> To: "Yaniv Kaul" <ykaul@redhat.com> Cc: users@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_AM...
That is pretty much what libvirt does. The sandy-bridge, haswell and other cpu's that we expose are not really a CPUs, but sets of flags (called baseline CPUs in libvirt's terminology). Afaik there should be no issue running cluster with both CPU vendors, the problem is lack of testing on devel side as we mostly run single vendor clusters everywhere.
"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
participants (3)
-
Martin Polednik -
Matthew Trent -
Yaniv Kaul