Azure WVD - Host Pool Scaling plan not working?

Question

Azure WVD - Host Pool Scaling plan not working?

Andrea Tordin 20

Hello,

I have an host pool on Azure WVD with 30 session hosts with Windows 10 Single Session. My goal is to have only 1 VM in running state other than the VM running with 1 user session, the rest turned off. I have configured the pool Scaling Plan with the following options:

In General:

Repeat on: Everyday

In Ramp-up:

Start time (12 hour system): 06:00 AM
Load balancing algorithm: Depth-first- Minimum percentage of hosts (%): 3
Capacity threshold (%): 90

In Peak hours:

Start time (12 hour system): 08:00 AM
Load balancing algorithm: Depth-first
Capacity threshold (%): 90

In Ramp-down:

Start time (12 hour system): 07:00 PM
Load balancing algorithm: Depth-first
Minimum percentage of active hosts (%): 3
Capacity threshold (%): 90
Force sign out users: No
Stop VMs when: VMs have no active sessions
In Off-peak hours:
Start time (12 hour system): 08:00 PM
Load balancing algorithm: Depth-first
Capacity threshold (%): 90

With this configuration the scaling works correctly except for the VMs that leaves in running that don't have a session on, it seems that the pool always has at least 2 VMs without session in running, and I only want 1. Is the configuration correct? Why in Peak hours i am not able to select the percentage of hosts without a session I want to leave running?

Lijitha B 515 Reputation points Moderator

2024-10-22T14:40:04.88+00:00

Hi Andrea Tordin,

Welcome to the Microsoft Q&A Platform! Thank you for asking your question here.

You want to keep just one VM running alongside the active session host in your Azure WVD setup, but the scaling plan is consistently leaving two idle VMs active. Need to adjust your scaling plan settings.

Adjust the Minimum percentage of active hosts in both the Ramp-up and Ramp-down settings from 3% to 1%. This adjustment will help reduce the number of idle VMs. Make sure that the option to stop VMs when there are no active sessions is enabled, ensuring that any unused VMs are powered off. Review the peak hours settings to verify they align with your objectives. Although you can't set specific limits for idle VMs, ensure that your overall capacity management strategy supports your goals. After implementing these changes, monitor the behavior of the host pool throughout the day to confirm that only one idle VM remains active.

If you feel that your quires have been resolved, if it was helpful, please click "Upvote" on his post to let us know.
Andrea Tordin 20 Reputation points

2024-10-23T09:16:42.8466667+00:00

Hello,

Thank you for your response, I have configured to 3% as I have 30 hosts and to leave 1 host in running I tought that 3% of 30 ~= 1 host to leave in running state. I have also already tried to put 2% with no luck. I will follow your suggestion by putting 1% in the Minimum percentage of hosts (%) setting in both Ramp-up and Ramp-down tabs and will monitor the behaviour of the pool.

By the way, this problem got me wondering why the Peak hours tab doesn't have the Minimum percentage of hosts (%) setting and if perhaps there is a standard value of hosts that the Scaling Plan leaves in running during the so called Peak hours period.

I will let you know the results of the operations I performed following your suggestions.

Thanks and regards,

Andrea.
Andrea Tordin 20 Reputation points

2024-10-23T14:59:09.7833333+00:00

Hello again,

So I've figured out the problem with the configuration:

The setting "Minimum percentage of hosts (%):" was actually fine with the set value 3, the setting I was not considering is Capacity threshold (%): which was configured with set value of 90. To get only 1 running VM as mentioned in previous posts, I had to configure it to 96%. I still don't get its description and implementation, as the desc. says, this parameter should work only with multisession VMs, but apparently it works with single session VMs too. The pool now correctly leaves 1 VMs in running and the rest stopped, aside from running VMs with a session.

P.S. The peak hours tab seems to carry on ramp-up settings, same with off-peak hours and ramp down tabs.

Accepted answer

0 additional answers

Your answer

Lijitha B 515 Reputation points Moderator

2024-10-22T14:40:04.88+00:00

Hi Andrea Tordin,

Welcome to the Microsoft Q&A Platform! Thank you for asking your question here.

You want to keep just one VM running alongside the active session host in your Azure WVD setup, but the scaling plan is consistently leaving two idle VMs active. Need to adjust your scaling plan settings.

Adjust the Minimum percentage of active hosts in both the Ramp-up and Ramp-down settings from 3% to 1%. This adjustment will help reduce the number of idle VMs. Make sure that the option to stop VMs when there are no active sessions is enabled, ensuring that any unused VMs are powered off. Review the peak hours settings to verify they align with your objectives. Although you can't set specific limits for idle VMs, ensure that your overall capacity management strategy supports your goals. After implementing these changes, monitor the behavior of the host pool throughout the day to confirm that only one idle VM remains active.

If you feel that your quires have been resolved, if it was helpful, please click "Upvote" on his post to let us know.
Andrea Tordin 20 Reputation points

2024-10-23T09:16:42.8466667+00:00

Hello,

Thank you for your response, I have configured to 3% as I have 30 hosts and to leave 1 host in running I tought that 3% of 30 ~= 1 host to leave in running state. I have also already tried to put 2% with no luck. I will follow your suggestion by putting 1% in the Minimum percentage of hosts (%) setting in both Ramp-up and Ramp-down tabs and will monitor the behaviour of the pool.

By the way, this problem got me wondering why the Peak hours tab doesn't have the Minimum percentage of hosts (%) setting and if perhaps there is a standard value of hosts that the Scaling Plan leaves in running during the so called Peak hours period.

I will let you know the results of the operations I performed following your suggestions.

Thanks and regards,

Andrea.
Andrea Tordin 20 Reputation points

2024-10-23T14:59:09.7833333+00:00

Hello again,

So I've figured out the problem with the configuration:

The setting "Minimum percentage of hosts (%):" was actually fine with the set value 3, the setting I was not considering is Capacity threshold (%): which was configured with set value of 90. To get only 1 running VM as mentioned in previous posts, I had to configure it to 96%. I still don't get its description and implementation, as the desc. says, this parameter should work only with multisession VMs, but apparently it works with single session VMs too. The pool now correctly leaves 1 VMs in running and the rest stopped, aside from running VMs with a session.

P.S. The peak hours tab seems to carry on ramp-up settings, same with off-peak hours and ramp down tabs.

Answer 1

Hi Andrea Tordin,

I'm glad that you were able to resolve your issue and thank you for posting your solution so that others experiencing the same thing can easily reference this! Since the Microsoft Q&A community has a policy that "The question author cannot accept their own answer. They can only accept answers by others ", I'll repost your solution in case you'd like to "Accept " the answer.

Issue: You have an Azure WVD host pool with 30 session hosts and want to keep only 1 VM running (besides the one with an active user session) while the others are turned off. Your scaling plan has a minimum percentage of active hosts set to 3%, which seems to result in at least 2 VMs remaining active without sessions. In Peak hours, you can't specify a percentage for idle hosts to remain running. The configuration needs adjustments to meet your goal.

Solution: The setting "Minimum percentage of hosts (%):" was actually fine with the set value 3, the setting I was not considering is Capacity threshold (%): which was configured with set value of 90. To get only 1 running VM as mentioned in previous posts, I had to configure it to 96%.

If you have any other questions or are still running into more issues, please let me know. Thank you again for your time and patience throughout this issue.

Please remember to "Accept Answer" if any answer/reply helped, so that others in the community facing similar issues can easily find the solution.

Share via

Azure WVD - Host Pool Scaling plan not working?

0 additional answers

Your answer