VM prioritization for DRS configuration

Question

VM prioritization for DRS configuration

Kaushal, Pravesh 125

Hi,

In Azure VMware Solution, can we enable DRS for VMs with associated priority levels to enable configuration of DRS prioritization during AVS migration?

With regards to restart order in case of a HA event, is there a way to set this, you certainly can't do it in the vCenter UI and I can't see a way to do this in the Azure Portal.

Regards

PK

Manish Deshpande 8,135 Reputation points Microsoft External Staff Moderator

2026-05-06T02:43:01.0566667+00:00
Hello Kaushal

Thanks for the great questions you've touched on two related but distinct areas in AVS, so let me address them separately.

DRS VM Prioritization During AVS Migration

You're right that direct DRS rule management from the vSphere Client is restricted in AVS — that's by design since the cluster is a managed resource. The supported way to achieve this is through Placement Policies in the Azure Portal.

Placement Policies let you control how VMs are distributed across hosts in your cluster, and behind the scenes they create the corresponding DRS rules for you. The types available are:

VM-VM Affinity – keep specific VMs together on the same host

VM-VM Anti-Affinity – spread VMs across separate hosts (great for resilience during migration)

VM-Host Affinity / Anti-Affinity** – control which hosts specific VMs prefer or avoid

One thing worth noting: VM-Host policies in AVS are always treated as preferential ("should" rules), not hard requirements. This is intentional so platform operations like host maintenance or replacement aren't blocked.

To create a Placement Policy:

→ Azure Portal > Your Private Cloud > Manage > Placement Policies > + Create

https://learn.microsoft.com/en-us/azure/azure-vmware/create-placement-policy

VM Restart Order During an HA Event

This one's a bit different. You're correct that you can't configure HA restart order from the Azure Portal or the vCenter UI directly in the usual way — but it is configurable through vCenter using a combination of VM Groups, VM/Host Rules, and VM Overrides under the CloudAdmin role.

Here's the approach that works well:

Step 1 – Adjust the HA Restart Condition

In vCenter → Cluster → Configure → vSphere Availability → Edit, set the VM dependency restart condition to "Guest Heartbeats Detected"**. This ensures the next tier of VMs won't start until the previous group's OS is actually up and VMware Tools heartbeat is confirmed — not just when resources are allocated.

Step 2 – Create VM Groups

Cluster → Configure → VM/Host Groups → Add

Group your VMs by restart tier, e.g., "Tier1-DatabaseVMs", "Tier2-AppVMs", "Tier3-WebVMs".

Step 3 – Create Dependency Rules

Cluster → Configure → VM/Host Rules → Add

Use type "Virtual Machines to Virtual Machines" to define the order — e.g., Tier2 only starts after Tier1's restart condition is met.

Step 4 – Set Per-VM Restart Priority (Optional but Recommended)

Cluster → Configure → VM Overrides → Add

Assign priorities (Lowest / Low / Medium / High / Highest) to individual VMs for finer control within each tier.

Broadcom KB (VM start order with HA):
https://knowledge.broadcom.com/external/article/408683

A couple of AVS-specific things to keep in mind:

DRS VM-VM Anti-Affinity rules require at least N+1 hosts in the cluster (where N = number of VMs in the rule). If you're scaling in, keep this in mind to avoid rule conflicts.

Avoid configuring any VM with a "Must run on host" DRS rule — AVS platform operations like host remediation may conflict with this and could result in brief VM disruption.

AVS Maintenance Best Practices:
https://learn.microsoft.com/en-us/azure/azure-vmware/azure-vmware-solution-private-cloud-maintenance

Thanks,
Manish.
Manish Deshpande 8,135 Reputation points Microsoft External Staff Moderator

2026-05-09T01:19:17.0566667+00:00

Hello @Kaushal, Pravesh

I wanted to check if my last response made sense. I’d be glad to assist further or explain anything in more detail and please accept as Yes and upvote if the answer is helpful so that it can help others in the community.

2 answers

Your answer

Manish Deshpande 8,135 Reputation points Microsoft External Staff Moderator

2026-05-09T01:19:17.0566667+00:00

Hello @Kaushal, Pravesh

I wanted to check if my last response made sense. I’d be glad to assist further or explain anything in more detail and please accept as Yes and upvote if the answer is helpful so that it can help others in the community.

Answer 1

kagiyama yutaka 5,330

Avs has drs priority / ha order locked in the mgmt‑plane, so u just shape where the vm sits w/ placement‑policy…if it still drifts, peek host‑drs once, then pass it to ms support.

0 comments

Answer 2

In Azure VMware Solution, Distributed Resource Scheduler (DRS) is fully managed and CloudAdmin cannot directly configure DRS rules or per‑VM DRS priority in vCenter. Instead, AVS exposes a limited, supported control surface via placement policies in the Azure portal.

For VM placement and movement behavior:

Placement policies create and manage the underlying DRS rules on the cluster on your behalf; CloudAdmin can only view these rules in vSphere, not edit them.
Supported controls include:
- VM–Host affinity/anti‑affinity (to constrain which hosts a VM can run on).
- “Restrict VM movement” to prevent DRS‑initiated vMotion for selected VMs (DRS is set to partially automated for those VMs; only manual vMotion and automatic initial placement occur).
There is no exposed mechanism in AVS to assign DRS priority levels to individual VMs for load balancing or migration decisions beyond what these placement policies provide.

Regarding restart order during HA events:

The provided AVS documentation and placement policy feature set do not expose any configuration for VM restart priority or restart order for vSphere HA within AVS, either in vCenter (for CloudAdmin) or in the Azure portal.
AVS manages the infrastructure‑level HA behavior; customers can influence where VMs run (via DRS affinity/anti‑affinity and placement policies) but not the HA restart sequence.

So, in AVS today:

DRS per‑VM priority configuration is not available to CloudAdmin.
HA restart order/priority configuration is not available via vCenter UI or Azure portal.
VM placement control is limited to supported placement policies (VM‑Host affinity/anti‑affinity and Restrict VM movement) and standard DRS behavior.

References: