VMware Cloud Community
ASThorpe
Contributor
Contributor

Workload balancing taking into account Host Rules

Can anyone help?

I have a (theoretical) cluster of 11 identical hosts, and with host rules they are split for licensing purposes, 5 for Windows and 5 for Linux plus one dedicated failover host (licensed for both, just in case!). The rules are set to 'must' and all VM's are in one of the two groups.

The average usage is around 50% CPU and 50% memory and everything, from a cluster level, looks fine (if a little underutilised...).

However, we have an imbalance of VM's and thus both the CPU and memory utilisation of the Windows hosts is over 90% each, yet the Linux hosts is below 10%.

Does vRealise recognise the host rules?

Would it understand the host rules when (and if) it tries to balance the workload?

Would we be able to see this from a cluster level?

Many thanks in advance,

Andy

vSphere ver: 6.5

vROPs ver: 6.6

3 Replies
daphnissov
Immortal
Immortal

Yes, it will respect these DRS affinity rules and will not attempt to move VMs to ineligible hosts. I'm not sure, though, what you're looking to "see" in this case within vCenter other than a migration to other hosts which *are* eligible.

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ASThorpe
Contributor
Contributor

Thanks daphnissov,

I understand that it will respect the DRS affinity rules and not move them but does vRealize know of these rules in advance or does it instruct vSphere to move them, then see the DRS rule and stop.

Also, I guess I'm not being clear on what I want to "see"...

What I mean is can you produce the capacity reports, workload balancing, etc based on a "host group" (Linux or Windows in my case) rather than at the full cluster level?  Seeing that the cluster is running at 50% utilisation is pretty useless if half of my hosts are overloaded and running at 100%!

Thinking about it, would it be something I could achieve by creating a custom datacenter with the linux hosts and another with the windows hosts?

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daphnissov
Immortal
Immortal

Yes, vROps knows of these rules and so there won't be an "attempt" to move it and then vSphere stops it. For the capacity reports, you'd probably need to use a custom datacenter because vROps doesn't know your intention or justification behind those DRS rules.