Evacuate ESXi host without DRS

One of the biggest draws to vSphere Enterprise Plus licensing is the Distributed Resource Scheduler feature. DRS allows for recommendations and automated actions to help balance virtual machine workloads across hosts, as well as affinity rules to keep VMs on or off of specific hosts. 

One of the more common functions is the ability to automatically migrate virtual machines off hosts when they are placed in maintenance mode to perform firmware or hardware upgrades. I set out to create a script that would do this for me on a vSphere Standard license. That script can be found here: https://github.com/ThisGuyFuchs/Evacuate-ESXi-Host-without-DRS

The script is pretty straightforward:

# Connect to vCenter Server
Connect-VIServer -Server "Your-vCenter-Server" -User Your-Username -Password Your-Password

Replace "Your-vCenter-Server" with the IP address or FQDN of your vCenter, as well as the administrator account (mine for example is administrator@vsphere.local) and the password for that account. You can remove -Password if you want it to prompt for it instead.

# Specify the ESXi host to evacuate
$esxiHost = "ESXi-Host-Name"

Replace "ESXi-Host-Name" with the IP address or the FQDN of the host you wish to evacuate.

From there, the script will generate a list of VMs, regardless of power state, and then migrate those VMs to any powered on host in the cluster. Once the script finishes, you are free to put the host into maintenance mode manually, or you can add this step to the script with:

# Put the ESXi host into maintenance mode
Set-VMHost -VMHost $esxiHost -State Maintenance -Confirm:$false

Keep in mind that this will migrate ALL virtual machines, whether they are powered on or off. While this isn't a true replacement to DRS, I find this useful to facilitate firmware updates and add hardware to hosts when needed. Hopefully this can provide additional value to vSphere Standard license holders.