What would cause an LCM pre-check event with the test_esx_entering_mm_pinned_vms check during an AOS upgrade?

The LCM pre-check testesxenteringmmpinnedvms is designed to identify virtual machines that cannot be migrated from an ESXi host, which is a required step for the host to enter maintenance mode during an upgrade. A "pinned" VM is one that is prevented from moving. VMware Distributed Resource Scheduler (DRS) VM-Host affinity rules are a primary cause for this condition. If a "must run on" rule is configured, it forces a VM to stay on a specific host, blocking any vMotion attempts and causing this pre-check to fail.

A. HA priority settings determine the restart order of VMs after a host failure; they do not restrict a VM's ability to be migrated for maintenance.
B. Insufficient memory on other hosts could prevent migration, but this is a resource availability issue, not a configuration that "pins" the VM to its current host.
C. High CPU usage does not inherently prevent vMotion. While extreme usage might slow down the migration, it is not a configuration that pins the VM.

1. Nutanix Knowledge Base Article 4531: This article specifically addresses the testesxenteringmmpinnedvms pre-check.

Reference: Nutanix Support Portal, KB 4531, "LCM Pre-check: testesxenteringmmpinnedvms".

Quote/Paraphrase: The article states, "This check verifies if there are any 'pinned' VMs on the ESXi hosts... Pinned VMs are VMs that cannot be migrated from the host." Under the "Cause" section, it explicitly lists "VM-Host affinity rules" as a primary reason for this check to fail.

2. Nutanix Life Cycle Manager (LCM) Guide: This guide explains the purpose of LCM pre-checks, which is to ensure a cluster is in a healthy state and ready for an upgrade without disruption.

Reference: Life Cycle Manager Guide v2.6, Chapter: "Performing a Software Update", Section: "Pre-Upgrade Checks".

Quote/Paraphrase: The guide details that LCM runs a comprehensive set of pre-checks before starting an upgrade to detect any issues that could interfere with the process, such as a host's inability to enter maintenance mode. This aligns with the function of the testesxenteringmmpinnedvms check.