Hi Scott, Click on a vm Edit Show Advanced Options Host "Start Running on"

Sven, If I tag the VMs as db-servers can I then say run on different hosts. On the static "Start running on", if that host goes down, it will migrate, yes?

I think what the OP is asking for a designation as a "redundant group 1". He may have 10 hosts and 3 VMs in "redundant group 1". He doesn't care which hosts they run on, as long as they are three separate hosts. I can see this as being fairly widely applicable. If you have multiple web servers for load sharing, you don't want them all running on the same host, because VM load is going to peak on them at the same times. oVirt has no way of knowing that unless you give oVirt a hint to spread things around. The web group might also want to split up the server that spreads the jobs around, and a database server used by all the web hosts. I can see easily ending up with a group of 5 machines (3 web servers, a load sharing controller, and a database server) that you want spread across any 5 of the 15 servers in a cluster, because their loads are all going to spike together. You don't want oVirt having to try to migrate some of them during a load spike, because oVirt noticed that a host with 3 of the 5 is overloaded. Not my situation, but one I can see the usefulness of. Ted Miller Elkhart, IN, USA On 3/18/2014 11:54 AM, Meital Bourvine wrote: > Hi Scott, > > Click on a vm > Edit > Show Advanced Options > Host > "Start Running on" > > ----- Original Message ----- >> From: "Scott Ocken" <scott(a)infobunker.com&gt; >> To: Users(a)ovirt.org >> Sent: Tuesday, March 18, 2014 5:08:24 PM >> Subject: [Users] Force certain VMs to be on different hosts >> >> Is there a way to have certain VMs to be on different hosts? (assuming >> there are enough hosts) >> >> IE. I have a db cluster of 3 VMs. I would like each one to always be >> on different hosts. That way if a host goes down my db cluster is >> still happy while migration happens. Or if migration fails I am still >> good. >> >> Thanks >> Scott >> >> _______________________________________________ >> Users mailing list >> Users(a)ovirt.org >> http://lists.ovirt.org/mailman/listinfo/users >> > _______________________________________________ > Users mailing list > Users(a)ovirt.org > http://lists.ovirt.org/mailman/listinfo/users -- "He is no fool who gives what he cannot keep, to gain what he cannot lose." - - Jim Elliot For more information about Jim Elliot and his unusual life, see http://www.christianliteratureandliving.com/march2003/carolyn.html. Ted Miller Design Engineer HCJB Global Technology Center, a ministry of Reach Beyond 2830 South 17th St Elkhart, IN 46517 574--970-4272 my desk 574--970-4252 receptionist _______________________________________________ Users mailing list Users(a)ovirt.org http://lists.ovirt.org/mailman/listinfo/users

From: "Ted Miller" <tmiller(a)hcjb.org&gt; To: users(a)ovirt.org Sent: Monday, March 24, 2014 8:27:31 PM Subject: Re: [Users] Force certain VMs to be on different hosts Scott On 3/19/2014 10:30 AM, Scott Ocken wrote: > Ted, > > Yes! This is exactly what I was looking for. I think you described it > better than I did. This feature would be really nice. > > Thanks > Scott > > Quoting Ted Miller <tmiller(a)hcjb.org&gt;: > >> I think what the OP is asking for a designation as a "redundant group 1". >> He may have 10 hosts and 3 VMs in "redundant group 1". He doesn't care >> which hosts they run on, as long as they are three separate hosts. >> >> I can see this as being fairly widely applicable. If you have multiple >> web servers for load sharing, you don't want them all running on the same >> host, because VM load is going to peak on them at the same times. oVirt >> has no way of knowing that unless you give oVirt a hint to spread things >> around. The web group might also want to split up the server that spreads >> the jobs around, and a database server used by all the web hosts. I can >> see easily ending up with a group of 5 machines (3 web servers, a load >> sharing controller, and a database server) that you want spread across any >> 5 of the 15 servers in a cluster, because their loads are all going to >> spike together. You don't want oVirt having to try to migrate some of them >> during a load spike, because oVirt noticed that a host with 3 of the 5 is >> overloaded. >> >> Not my situation, but one I can see the usefulness of. >> Ted Miller >> Elkhart, IN, USA >> >> On 3/18/2014 11:54 AM, Meital Bourvine wrote: >>> Hi Scott, >>> >>> Click on a vm >>> Edit >>> Show Advanced Options >>> Host >>> "Start Running on" >>> >>> ----- Original Message ----- >>>> From: "Scott Ocken" <scott(a)infobunker.com&gt; >>>> To: Users(a)ovirt.org >>>> Sent: Tuesday, March 18, 2014 5:08:24 PM >>>> Subject: [Users] Force certain VMs to be on different hosts >>>> >>>> Is there a way to have certain VMs to be on different hosts? (assuming >>>> there are enough hosts) >>>> >>>> IE. I have a db cluster of 3 VMs. I would like each one to always be >>>> on different hosts. That way if a host goes down my db cluster is >>>> still happy while migration happens. Or if migration fails I am still >>>> good. >>>> >>>> Thanks >>>> Scott >> >> Ted Miller It looks like the Negative Affinity/Anti-Affinity feature that Itamar Hein pointed out in his email, with a feature page at http://www.ovirt.org/Features/VM-Affinity includes what you are trying to do.

This is in 3.4, which in the QA process now.

Ted Miller Elkhart, IN, USA _______________________________________________ Users mailing list Users(a)ovirt.org http://lists.ovirt.org/mailman/listinfo/users

From: "noc" <noc(a)nieuwland.nl&gt; To: users(a)ovirt.org Sent: Monday, March 31, 2014 3:31:45 PM Subject: Re: [Users] Force certain VMs to be on different hosts On 25-3-2014 13:47, Gilad Chaplik wrote: > ----- Original Message ----- > As far as I know this feature is fully tested and verified for version > 3.4. I'd love for feedback! and would like to assist in anything :) I tried it and was suprised about the following: made an positive affinity group with two vms in it, then tried to migrate one vm and got a rather surprising and not quite helpful message. I expected that the second vm would be migrated after the first was done but the message is about something on the receiving host not being in working order. Sorry my memory is a bit vague about it. Will try later to day and reproduce if needed. Is what I describe possible/planned? Regards, Joop _______________________________________________ Users mailing list Users(a)ovirt.org http://lists.ovirt.org/mailman/listinfo/users

From: "Joop" <jvdwege(a)xs4all.nl&gt; To: "Gilad Chaplik" <gchaplik(a)redhat.com&gt; Cc: users(a)ovirt.org Sent: Friday, April 4, 2014 5:44:11 PM Subject: Re: [Users] Force certain VMs to be on different hosts Gilad Chaplik wrote: > Hi Joop, > > You've created a positive enforcing affinity group -> means that VMs should > stay on the same host, no migration allowed while more than one VM is up. > What you're requesting is a useful RFE, some-kind of a 'follow me' positive > affinity group. > I'm +1 on that :-) can you please open a formal request/RFE for it? > https://bugzilla.redhat.com/enter_bug.cgi?product=oVirt > > BZ opened: https://bugzilla.redhat.com/show_bug.cgi?id=1084518 Have read somewhere on the list that it should be possible to tag such a request as a FutureFeature but couldn't find it when creating the entry. Please feel free to move it and educate me!

Regards, Joop

Hi Scott, Don't want to get in deep into the thread... Does Affinity Groups feature what you're after (sounds like negative affinity) ? http://www.ovirt.org/Features/VM-Affinity

Thanks, Gilad. ----- Original Message ----- > From: "Scott Ocken" <scott(a)infobunker.com&gt; > To: Users(a)ovirt.org > Sent: Tuesday, March 18, 2014 5:08:24 PM > Subject: [Users] Force certain VMs to be on different hosts > > Is there a way to have certain VMs to be on different hosts? (assuming > there are enough hosts) > > IE. I have a db cluster of 3 VMs. I would like each one to always be > on different hosts. That way if a host goes down my db cluster is > still happy while migration happens. Or if migration fails I am still > good. > > Thanks > Scott > > _______________________________________________ > Users mailing list > Users(a)ovirt.org > http://lists.ovirt.org/mailman/listinfo/users > _______________________________________________ Users mailing list Users(a)ovirt.org http://lists.ovirt.org/mailman/listinfo/users