Author: Mike

In part 2, I shared the PowerCLI scripting I used to power on my entire lab environment in the correct order. In this final installment, I’ll take you through the scripting used to power everything down. Although you may think the process is just the reverse of what I covered in part 2, you’ll see there were some other things to consider and different approaches required.

Step 1 – Shutting Down Compute Cluster VMs

To begin the process, I’d need to shut down all VMs in the compute-a cluster. None of the VMs there are essential for running the lab, so they can be safely stopped at any time. I was able to do this by connecting to vCenter with PowerCLI and then using a ‘foreach’ loop to gracefully shut down any VMs in the ‘Powered On’ state.

"Connecting to vCenter Server ..." |timestamp
Connect-VIServer -Server 172.16.1.15 -User administrator@vsphere.local -Password "VMware9("

"Shutting down all VMs in compute-a ..." |timestamp
$vmlista = Get-VM -Location compute-a | where{$_.PowerState -eq 'PoweredOn'}
foreach ($vm in $vmlista)
    {
    Shutdown-VMGuest -VM $vm -Confirm:$false | Format-List -Property VM, State
    }

The above scripting ensures the VMs start shutting down, but it doesn’t tell me that they completed the process. After this is run, it’s likely that one or more VMs may still be online. Before I can proceed, I need to check that they’re all are in a ‘Powered Off’ state.

"Waiting for all VMs in compute-a to shut down ..." |timestamp
do
{
    "The following VM(s) are still powered on:"|timestamp
    $pendingvmsa = (Get-VM -Location compute-a | where{$_.PowerState -eq 'PoweredOn'})
    $pendingvmsa | Format-List -Property Name, PowerState
    sleep 1
} until($pendingvmsa -eq $null)
"All VMs in compute-a are powered off ..."|timestamp

A ‘do until’ loop does the trick here. I simply populate the list of all powered on VMs into the $pendingvmsa variable and print that list. After a one second delay, the loop continues until the $pendingvmsa variable is null. When it’s null, I know all of the VMs are powered off and I can safely continue.

Continue reading “Home Lab Power Automation – Part 3”

In part 1, I shared some of the tools I’d use to execute the power on and shutdown tasks in my lab. Today, let’s have a look at my startup PowerCLI script.

A Test-Connection Cmdlet Replacement

As I started working on the scripts, I needed a way to determine if hosts and devices were accessible on the network. Unfortunately, the Test-Connection cmdlet was not available in the Linux PowerShell core release. It uses the Windows network stack to do its thing, so it may be a while before an equivalent gets ported to Linux. As an alternative, I created a simple python script that achieves the same overall result called pinghost.py. You can find more detail on how it works in a post I did a few months back here.

The script is very straightforward. You specify up to three space separated IP addresses or host names as command line arguments, and the script will send one ICMP echo request to each of the hosts. Depending on the response, it will output either ‘is responding’ or ‘is not responding’. Below is an example:

pi@raspberrypi:~/scripts $ python pinghost.py vc.lab.local 172.16.10.67 172.16.10.20
vc.lab.local is not responding
172.16.10.67 is responding
172.16.10.20 is not responding

Then using this script, I could create sleep loops in PowerShell to wait for one or more devices to become responsive before proceeding.

Adding Timestamps to Script Output

As I created the scripts, I wanted to record the date/time of each event and output displayed. In a sense, I wanted it to look like a log that could be written to a file and referred to later if needed. To do this, I found a simple PowerShell filter that could be piped to each command I ran:

#PowerShell filter to add date/timestamps
filter timestamp {"$(Get-Date -Format G): $_"}

Step 1 – Power On the Switch

Powering up the switch requires the use of the tplink_smartplug.py python script that I discussed in part 1. The general idea here is to instruct the smart plug to set its relay to a state of ‘1’. This brings the switch to life. I then get into a ‘do sleep’ loop in PowerCLI until the Raspberry Pi is able to ping the management interface of the switch. More specifically, it will wait until the pinghost.py script returns a string of “is responding”. If that string isn’t received, it’ll wait two seconds, and then try again.

"Powering up the 10G switch ..." |timestamp
/home/pi/scripts/tplink-smartplug-master/tplink_smartplug.py -t 192.168.1.199 -c on |timestamp

"Waiting for 10G switch to boot ..." |timestamp
do
{
$pingresult = python ~/scripts/pinghost.py 172.16.1.1 |timestamp
$pingresult
sleep 2
} until($pingresult -like '*is responding*')

When run, the output looks similar to the following:

Continue reading “Home Lab Power Automation – Part 2”

My home lab has grown substantially over the last few years and with it, so did power consumption, heat and noise. I selected power efficient parts where possible, but even with 500-600W power usage, 24/7 operation adds up. I can certainly notice the extra cost on my hydro bill, but it’s not just the financial impact – it’s also the environmental impact I’m concerned about.

The bottom line is that I have no reason to run the lab 24/7. I generally use it an hour or two each day – sometimes more, sometimes less. But there are also stretches where I won’t use it for several days like on weekends or when I’m busy with other things.

I found myself manually shutting down the lab when I knew I wouldn’t be using it and then manually powering everything back up. As you can imagine, this was quite a process. Everything had to be powered on or shut down in a very specific order to avoid problems. I’d also need to be standing in front of the equipment for part of this process as some equipment didn’t have remote power-on capability. Because of the work and time involved, I’d inevitably just leave it powered on for much longer stretches than I needed to.

It wasn’t until I added a 10Gbps Quanta LB6M switch to the lab that I realized I needed to do something. It’s not a quiet or energy efficient switch, consuming an average of 120W at idle.

Continue reading “Home Lab Power Automation – Part 1”