Upgrade NSX to 4.x- do hosts need to be rebooted?

[JDMils_Interact]

We are currently using NSXT v3.2.4.0.0.23653566 and will be upgrading to NSXT 4.2.2.1 and I have read the release notes (Upgrade Guide) and I'm still confused as to whether the hosts need to be rebooted after being upgraded?

I believe the process is:

• Upgrade the controllers.
• Upgrade the hosts.
• Upgrade the edges

Is this correct?

[Sriram ChunchankatteMelukote]

Yes the upgrade order of the components you listed is correct. Also by default post the upgrade,hosts will not ask for reboot unless you have manually set any host group settings to reboot after the upgrade. 

In case of the DRS recommendations being logged, user will have to manually migrate VMs out of the host, before the host getting upgraded.

[Bogdan_Ionut]

When upgrading from NSX-T 3.2.x to NSX 4.x, ESXi hosts do not require a reboot by default. NSX kernel modules are upgraded live, and reboots occur only if explicitly configured or required by ESXi itself.

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