
Hi all, Situation as follows: mixed cluster with 3.5 and 3.6 nodes. Now in the process of reinstalling the 3.5 nodes with 3.6 on CentOS 7.2. I can't live migrate VM's while they're running on different versions. That's odd, but not the weirdest issue. The most interesting part is happening when I power down a VM, and then run it on a 3.6 node. Only on CentOS 7 VM's, I'm getting a "no bootable device" error. I have a mixed setup of ubuntu, CentOS 6 and CentOS 7. Ubuntu & CentOS 6 are fine. Tried shooting grub in MBR again, to no effect. I start the VM then on a 3.5 node and all is fine. -- Met vriendelijke groeten / With kind regards, Johan Kooijman

Johan Kooijman <mail@johankooijman.com> writes:
Situation as follows: mixed cluster with 3.5 and 3.6 nodes. Now in the process of reinstalling the 3.5 nodes with 3.6 on CentOS 7.2. I can't live migrate VM's while they're running on different versions.
Live migration should always work within a single cluster. What do Vdsm logs say on both the source and target hosts when the migration fails?
The most interesting part is happening when I power down a VM, and then run it on a 3.6 node. Only on CentOS 7 VM's, I'm getting a "no bootable device" error. I have a mixed setup of ubuntu, CentOS 6 and CentOS 7. Ubuntu & CentOS 6 are fine.
Tried shooting grub in MBR again, to no effect. I start the VM then on a 3.5 node and all is fine.
So the VM is indicated as starting in Engine and BIOS or GRUB can't find the device to boot from? Could you provide Vdsm logs from both successful and unsuccessful boot of the same VM?

On 22 Jul 2016, at 10:32, Milan Zamazal <mzamazal@redhat.com> wrote:
Johan Kooijman <mail@johankooijman.com> writes:
Situation as follows: mixed cluster with 3.5 and 3.6 nodes. Now in the process of reinstalling the 3.5 nodes with 3.6 on CentOS 7.2. I can't live migrate VM's while they're running on different versions.
Live migration should always work within a single cluster.
not in case of EL6 to EL7 migration in 3.5. You can’t migrate from EL7 to EL6 host. There’s anew policy added in recent 3.6.z to allow mixed hosts in a single cluster, but that doesn’t change the fact that VMs can’t migrate back.
What do Vdsm logs say on both the source and target hosts when the migration fails?
The most interesting part is happening when I power down a VM, and then run it on a 3.6 node. Only on CentOS 7 VM's, I'm getting a "no bootable device" error. I have a mixed setup of ubuntu, CentOS 6 and CentOS 7. Ubuntu & CentOS 6 are fine.
Tried shooting grub in MBR again, to no effect. I start the VM then on a 3.5 node and all is fine.
it is reproducible by simply trying to run the VM on either EL6 or EL7 host, correct?
So the VM is indicated as starting in Engine and BIOS or GRUB can't find the device to boot from? Could you provide Vdsm logs from both successful and unsuccessful boot of the same VM?
can you create a new “normal” 3.6 cluster and move/add one of the EL7 hosts there, and move the VM to that new cluster and try it there? Thanks, michal
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Hi Johan, I had similar problems with some VM’s when moving VM’s to oVirt 3.6 from older versions. Iirc it was unable to find the disk device at all. The weird pard is that when I booted VM with recovery cd everything was ok. I was able to boot VM’s when I enabled boot menu from VM options (Boot options - Enable boot menu). Can you try if that helps in your case? Best regards, Samuli Heinonen
On 20 Jul 2016, at 15:12, Johan Kooijman <mail@johankooijman.com> wrote:
Hi all,
Situation as follows: mixed cluster with 3.5 and 3.6 nodes. Now in the process of reinstalling the 3.5 nodes with 3.6 on CentOS 7.2. I can't live migrate VM's while they're running on different versions. That's odd, but not the weirdest issue.
The most interesting part is happening when I power down a VM, and then run it on a 3.6 node. Only on CentOS 7 VM's, I'm getting a "no bootable device" error. I have a mixed setup of ubuntu, CentOS 6 and CentOS 7. Ubuntu & CentOS 6 are fine.
Tried shooting grub in MBR again, to no effect. I start the VM then on a 3.5 node and all is fine.
-- Met vriendelijke groeten / With kind regards, Johan Kooijman _______________________________________________ Users mailing list Users@ovirt.org http://lists.ovirt.org/mailman/listinfo/users
participants (4)
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Johan Kooijman
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Michal Skrivanek
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Milan Zamazal
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Samuli Heinonen