Beware: Windows Server 2012 reboot loop after November or December 2019 SSU patch

In November and December 2019, Microsoft released a few new patches just like any other month to patch certain issues in Windows Server 2012. It has recently come to my attention that these patches seem to break Windows Server 2012 virtual machines! They appear to cause a reboot loop, which …

How to fix Veeam VM replication error ‘The given key was not present in the dictionary.’

Recently I’ve been getting an error on one of my replication jobs in one of our Veeam environments. The error message was a bit vague, and to be honest, I’ve never seen it anywhere behore. The error message was: If you browse to your log file location, usually under: You …

How to fix: vSphere VUM: GUI error that prevents upgrades!

If you, as a vSphere Administrator, regularly update a vSphere environment you should be using vSphere Update Manager. vSphere Update Manager is the tooling that VMware made so that you don’t have to install patches through the command line on each host, or do updates on each host separately! And …

Remediating Host with ESXi 6.5 VUM “The host returns esxupdate error code:15 error

The other day I was patching a couple of hosts on one of our environments. All worked out fine until I got one host that refused to update from vSphere ESXi 6.5 U1 to ESXi 6.5 U3. Throughout the day this host actually gave me loads of different errors. In …

Slow boot times ESXi with (p/v)RDM’s easy fix

Recently we have been having (extremely) slow boot times for a couple of hosts that we’ve been using for a new customer. We actually didn’t really notice this in the beginning, until we added hosts to the existing cluster and the reboot for that host took over 3 hours! The …