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RE: [DISCUSS] deployment planner improvement

I think that this affects all hypervisors as CloudStack's deployment strategies are generally sub-optimal to say the least.
From what our devs have told me, a large part of the problem is that capacity/usage and suitability due to tags is calculated by multiple parts of the code independently, there is no central method, which will give a consistent answer.  

In Trillian we take a micro-management approach and have a custom module which will return the least used cluster, the least used host or the least used host in a given cluster.  With that info we place VMs on a specific hosts - keeping virtualised hypervisors in the same cluster (least used) so that processor types match, and all other VMs on the least used hosts.

For cross-cluster migrations (VMs and/or storage) I think that most times people want to move from cluster A to the least used (cluster/storage) in cluster B - making them choose which host/pool is actually unhelpful.

#scopecreep - sorry Pierre-Luc

Kind regards,

Paul Angus

Amadeus House, Floral Street, London  WC2E 9DPUK

-----Original Message-----
From: Will Stevens <wstevens@xxxxxxxxxxxx> 
Sent: 06 September 2018 19:45
To: dev@xxxxxxxxxxxxxxxxxxxxx; Marc-Andre Jutras <mjutras@xxxxxxxxxxxx>
Subject: Re: [DISCUSS] deployment planner improvement

If I remember correctly, we see similar issues on VMware.  Marcus, have you seen similar behavior on VMware?  I think I remember us having to manually vMotion a lot of VMs very often...

*Will Stevens*
Chief Technology Officer
c 514.826.0190


On Thu, Sep 6, 2018 at 2:34 PM Pierre-Luc Dion <pdion@xxxxxxxxxxxx> wrote:

> Hi,
> I'm working with a University in Montreal and we are looking at 
> working together to improve the deployment planner. Mainly for post 
> VM.CREATE tasks.
> Because  what we observed with cloudstack, in our case with XenServer, 
> overtime, a cluster will become unbalanced in therm of workload, vm HA 
> will move VMs all over the the cluster which cause hotspot inside a cluster.
> Also, when performing maintenance  xenmotion of VM spread them in the 
> cluster but does not consider host usage and at the end of a 
> maintenance it require manual operation to repopulate VMs on the last 
> host updated.  OS preference not taken into account  except for VM.CREATE.
> So,
> I'd like to work on improving VMs dispersion during and post outage 
> and maintenances. when a cluster resources are added or removed.
> Would you have any more requirement, we will document a feature spec 
> in the wiki which I believe it's still a requirement ?
> Does using KVM have similar issues over time?
> I don't think it would make sense to cloudstack to automatically take 
> decision on moving VMs but for now create report of recommended action 
> to do and provide steps to do them. tbd.
> Cheers,
> PL