Posts

"Cannot execute upgrade script on host" during ESXi 6.5 upgrade

I was onsite at one of my customers to update a small VMware vSphere 6.0 U3 environment to 6.5 U2c. The environment consists of three hosts. Two hosts in a cluster, and a third host is only used to run a HPE StoreVirtual Failover Manager.

The update of the first host, using the Update Manager and a HPE custom ESX 6.5 image, was pretty flawless. But the update of the second host failed with “Cannot execute upgrade script on host”

High CPU usage on Citrix ADC VPX

While building a small Citrix NetScaler… ehm… ADC VPX (I really hate this name…) lab environment, I noticed that the fan of my Lenovo T480s was spinning up. I was wondering why, because the VPX VM was just running for a couple of minutes - without any load. But the task manager told me, that the VMware Workstation Process was consuming 25% (I have a Intel i5 Quad Core CPU) CPU. So VMware Workstation was just eating a whole CPU core without doing anything. I would not care, but the fan… And it reminded me, that I’ve seen an similar behaviour in various VPX deployments on VMWare ESXi.

Using Let's Encrypt DNS-01 challenge validation with local BIND instance

I’m using Let’s Encrypt certificates for a while now. In the past, I used the standalone plugin (TLS-SNI-01) to get or renew my certificates. But now I switched to the DNS plugin. I run my own name servers with BIND, so it was a very low hanging fruit to get this plugin to work.

To get or renew a certificate, you need to provide some kind of proof that you are requesting the certificate for a domain that is under your control. No certificate authority (CA) wants to be the CA, that hands you out a certificate for google.com or amazon.com…

EAPoL forwarding on NEC VoIP phones

A customer is running their PCs behind their VoIP phones. Nothing unusual, most VoIP phones I know have an embedded ethernet switch, so that you only need one cable to connect PC and VoIP phone to your network.

As part of a network security project, my colleague and I implemented IEEE 802.1X port-based Network access control at one of our customers networks. The setup consists of multiple Alcatel-Lucent Enterprise OmniSwitches (6450-P10 and 6860/E) and Aruba ClearPass.

Powering on a VM with shared VMDK fails after extending a EagerZeroedThick VMDK

I hope that you are not reading this blog post while searching for a solution for a failed cluster. If so, feel free to leave a comment if this blog post saved your evening or weekend. :)

Last friday, a change at one of my customers went horribly wrong. I was not onsite, but they contacted me during the night from friday to saturday, because their most important Windows Server Failover Cluster was unable to start after extending a shared VMDK.

What is in the bag?

Michael White published the third release of his “What is in the bag” blog post. In reference to this, I would like to share the content of my bag.

I used a RIMOWA Salsa business trolley for several years. Unfortunately, it broke in June 2017 and a repair was refused by RIMOWA. I was very disappointed of the product quality and the customer service experience with RIMOWA.

I decided to switch to a backpack, which felt much more comfortable than carrying or pulling the RIMOWA trolley.

Office 365 - Outlook keeps prompting for password

This is only a short blog post to  document a solution for a very annoying problem. After the automatic update of my Outlook to the latest Office 365 build (version 1809), it has started to prompting for credentials. I’m using Outlook to access a Microsoft Exchange 2016 server (on-premises), without any hybrid configuration. A pretty simple and plain Exchange 2016 on-prem deployment.

I knew, that it has to be related to Office 365, because the Outlook 2016 on my PC at the office was not affected. Only the two Office 365 deployments on my ThinkPad T480s and ThinkPad X250.

Vembu BDR Essentials - affordable backup for SMB customers

It is common that vendors offer their products in special editions for SMB customers. VMware offers VMware vSphere Essentials and Essentials Plus, Veeam offers Veeam Backup Essentials, and now Vembu has published Vembu BDR Essentials.

Vembu Technologies/ Vembu BDR Essentials/ Copyright by Vembu Technologies

Vembu Technologies/ Vembu BDR Essentials/ Copyright by Vembu Technologies

Backup is important. There is no reason to have no backup. According to an infographic published by Clutch Research at the World Backup Day 2017, 60% of all SMBs that lost all their data will shutdown within 6 months after the data loss. Pretty bad, isn’t it?

Exam prep & experience: VMware Certified Advanced Professional 6 - Data Center Virtualization Deployment Exam (VCAP6-DCV Deploy)

TL;DR: I have passed the VCAP6-DCV Deploy exam today. :) I want to thank Fred, Dominik, Frank and Jens-Henrik for kicking my ass. Without you, I would have taken the VCP 6.5 delta exam. Thank you!

As often, the whole thing started with a tweet. A tweet about my expiring VMware Certified Professional (VCP) certification.

To my surprise, several of my followers recommended to go for the VCAP6-DCV Deployment instead. Okay, so many smart people can’t be wrong.

Backup from a secondary HPE 3PAR StoreServ array with Veeam Backup & Replication

When taking a backup with Veeam Backup & Replication, a VM snapshot is created to get a consistent state of the VM. The snapshot is taken prior the backup, and it is removed after the successful backup of the VM. The snapshot grows during its lifetime, and you should keep in mind, that you need some free space in the datastore for snapshots. This can be a problem, especially in case of multiple VM backups at a time, and if the VMs share the same datastore.