Bug 952238

Summary: [RFE] Specify CPU per VM - with higher cpu models and migration
Product: Red Hat Enterprise Virtualization Manager Reporter: Itamar Heim <iheim>
Component: RFEsAssignee: Michal Skrivanek <michal.skrivanek>
Status: CLOSED ERRATA QA Contact: sefi litmanovich <slitmano>
Severity: unspecified Docs Contact:
Priority: unspecified    
Version: 3.1.0CC: gklein, iheim, istein, lpeer, melewis, michal.skrivanek, rbalakri, sherold
Target Milestone: ovirt-3.6.0-rcKeywords: FutureFeature
Target Release: 3.6.0Flags: sherold: Triaged+
Hardware: Unspecified   
OS: Unspecified   
URL: http://www.ovirt.org/Features/Cluster_parameters_override
Fixed In Version: ovirt-3-6-0-2 Doc Type: Enhancement
Doc Text:
Story Points: ---
Clone Of: 838490 Environment:
Last Closed: 2016-03-09 20:30:26 UTC Type: Bug
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: Virt RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Bug Depends On: 838490, 1236049    
Bug Blocks: 1302707    

Description Itamar Heim 2013-04-15 12:43:52 UTC
cloning bug 838490 to cover the use case with live migration (sub cluster level scheduling, sla, etc.)

+++ This bug was initially created as a clone of Bug #838490 +++

Today the CPU type is taken from the cluster level
eg.If the cluster is Westmere then all the VMs are launched with -cpu westmere

We need the ability to specify CPU per virtual machine.
The setting should allow the cluster type or any lower CPU level

--- Additional comment from Itamar Heim on 2013-04-01 05:33:04 EDT ---

Andrew - can you please elaborate on goal/reason here?
we have the -cpu host for performance.
I assume you don't want someone to set a VM to a lower cpu, rather only to a higher one, which may make it impossible to migrate, etc.

is this supposed to be like -cpu host, but "hopefully migrate-able"?

(switching to sla, as main consideration here will be scheduling)

--- Additional comment from Andrew Cathrow on 2013-04-07 22:06:59 EDT ---

User cases

1. Allow a virtual machine to maintain a static CPU configuration.
eg. User is running VM on westmere host and upgrades the host systems to sandybridge.
Just because we are using a SandyBridge based host it doesn't mean we want to expose that to the guest. The guest may need to keep a consistent CPU and hardware profile.

2. Best performance (+ migration and stability)
- 10 node cluster. 
- 8 nodes are westmere, 2 are sandybridge
- Cluster level set to "westmere"

Allow admin to run VM with hardcoded "sandybridge" CPU on one of the 2 applicable hosts. Support migration between compatible hosts.

Obviously this brings with it restrictions.
- If no sandbridge system is running (or has capacity) then the VM can't be run
- You can only migrate between the 2 sandybridge machines
- If only one sandybridge machine is running the host won't be able to go into maintenance mode since it can't live migrate to another host so the VM will need to be stopped first.

Comment 6 sefi litmanovich 2016-01-03 13:19:52 UTC
Verified with rhevm-3.6.2-0.1.el6.noarch according to attached test plan.
Test run:


Comment 9 errata-xmlrpc 2016-03-09 20:30:26 UTC
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.