CDP info from vSphere platform

For documentation purposes, I wanted to get an overview of all host connections to which switches they are connected, and which ports exactly. As luck would have it, VMware already has made some scripts to do this.

I adapted it to suit my needs:

$Hosts = Get-VMHost | sort -property Name

foreach ($vhost in $Hosts){

$vmh = Get-VMHost -Name $vhost

If ($vmh.State -ne "Connected") {

  Write-Output "Host $($vmh) state is not connected, skipping."

  }

Else {

  Get-View $vmh.ID | `

  % { $esxname = $_.Name; Get-View $_.ConfigManager.NetworkSystem} | `

  % { foreach ($physnic in $_.NetworkInfo.Pnic) {

    $pnicInfo = $_.QueryNetworkHint($physnic.Device)

    foreach( $hint in $pnicInfo ){

      # Write-Host $esxname $physnic.Device

      if ( $hint.ConnectedSwitchPort ) {

        $hint.ConnectedSwitchPort | select @{n="VMHost";e={$esxname}},@{n="VMNic";e={$physnic.Device}},DevId,PortId

        }

      }

    }

  }

}

}

To run this, simply copy this script to a file, open up powershell, connect to vcenter, and run it with:

.\VMHostCDPInfo.ps1 | Format-Table -AutoSize |Out-File cdpinfo.txt

It ignores all nics where it cannot retrieve any CDP info from, but other than that, you get a nice list, which you can put with your documentation which looks like:

VMHost          VMNic   DevId    PortId
------          -----   -----    ------
server01        vmnic0  switch01 GigabitEthernet1/25
server01        vmnic10 switch02 GigabitEthernet2/0/31

How to make ESXi crash

While looking at a VMware KBTV video, I saw a cool trick to make your ESXi host crash (which can be good for testing purposes):

From SSH, type: vsish -e set /reliability/crashMe/Panic 1

Apparently, I'm telling nothing new: Seaching for that string on Google, I found the links below for more info:

http://www.seancrookston.com/2012/01/09/forcing-a-kernel-dump-on-a-vsphere-host-the-purple-screen-of-death/

http://www.ntpro.nl/blog/archives/1388-Lets-create-some-Kernel-Panic-using-vsish.html

Unable to remove ESXi host from vCenter

I needed to remove an ESXi host from vCenter that I wanted to re-use, but I was unable to. After disconnecting the server, the "Remove" button was greyed out:

 Some searching gave the tip to remove it via PowerCLI (Remove-VMHost), but that did not work either:

It turned out the ESXi host could not be removed because it was part of a cluster.

Solution:

Move the ESXi host entry (which is disconnected) to the top of your vCenter tree, out of any cluster. Then re-run the Remove-VMHost command (most likely the Remove function will be visible in the GUI as well, but I just pressed up and enter in my PowerCLI screen, and it started to remove)