You may use the following VMware PowerCLI script to place a VMware ESXi host in maintenance mode.
<# .SYNOPSIS This script will place a VMware ESXi host in maintenance mode. .DESCRIPTION This script will place a VMware ESXi host in maintenance mode. .EXAMPLE Set-VMHost -VMhost HOST.DOMAIN.COM -State Maintenance. .AUTHOR Written by Noel Enrique Alvarez on Monday, April 15, 2019. #>
#Request the hostname of the VMware ESXi host
$HOSTNAME = Read-Host “What is the hostname of the VMware ESXi host?”
#Place the VMware ESXi host in maintenance mode
Set-VMHost -VMhost $HOSTNAME -State Maintenance
#End of script