Welcome to Opvizor


I am excited to welcome Opvizor as a new sponsor to my blog! This fairly young startup offers a unique approach to keep your vSphere environment healthy. It is not about real-time monitoring (there are already plenty of products that do this), but Opvizor analyzes your environment for compliance with best practices, and it knows about and detects lots of common issues, misconfigurations and mistakes. Its goal is to prevent issues before they happen.

Updated: [ALERT] Issue with the ESXi 5.5 U1 Driver Rollup ISO: Software iSCSI adapter crashes hostd


While browsing through the VMware Community Forums I stumbled over a thread that made me curious: A customer experienced serious issues after upgrading his vSphere environment to 5.5 Update 1. The ESXi hosts became unresponsive right after the Software iSCSI adapter was added.

Issue after upgrading your vCenter 5.5 U1 server from Windows 2012 to 2012 R2

Update 1 for vCenter Server 5.5 was recently released, and the Windows version now officially supports being installed on Windows Server 2012 R2. So far I had the 5.5 GA version running on a Windows Server 2012, and after installing the Update 1 (which went pretty smoothly) I thought that it's a good idea to now also upgrade the OS to 2012 R2.

I had successfully done this kind of in-place upgrade before with my two Domain Controllers and the Veeam Backup server, and I was not really expecting any big issues, but this time there was one: After the upgrade to 2012 R2 finished the VMware vSphere Web Client service failed to start! It took me some time to find the root cause of this, but in the end it was easy to fix ...

How to update your standalone host to ESXi 5.5 U1

My "How to update ESXi" posts are still very popular, so now - that ESXi 5.5 Update 1 is out,- I must post short instructions on how to update your standalone host to ESXi 5.5 Update 1 ... ;-)

How to speed up the installation of Windows Updates


We recently upgraded a vSphere 5.0 environment to 5.0 U3 and used the maintenance window of the vCenter server to also install missing Windows updates on this and the vCenter database SQL server (both running Windows 2008 R2).

A generously dimensioned downtime of four hours was communicated before the upgrade -, and we managed to finish all the work just in time. Why? Because it took two hours alone to install the Windows updates! 18 patches were missing, and they took ages to install, particularly the .NET Framework 4 patches. I tried all sorts of things to speed this up during the installation (stopping unnecessary services and the Virus scanner), but to no avail. Eventually the updates finished successfully, and later I took myself some time to find out why it took so long and what you can do about this. Here is what I found out ...