DefinIT Because if IT were easy, everyone would do it…


Book review: Networking for VMware Administrators

Posted by Sam McGeown

NetworkingForVMwareAdministratorsI recently got my hands on a copy* of Chris Wahl and Steve Pantol’s Networking for VMware Administrators and was very keen to read it – especially given the reputation of the authors. I came to the book as someone who is at CCNA level (although now expired) and someone who regularly designs complex VMware networks using standard and distributed switches. I would class myself as having a fairly decent understanding of networking, though not a networking specialist.

The book starts out at from a really basic level explaining OSI, what a protocol is etc. and builds on the foundation set out as it progresses. Part I of the book gives are really good explanation of not only the basics of networking, but a lot of the “why” as well. If you’ve done CCNA level networking exams then you will know most of this stuff – but it’s always good to refresh, and maybe cover any gaps.

Part II of the book translates the foundations set out in Part I into the virtual world and takes you through the similarities and differences with between virtual and physical. It gives a good overview of the vSphere Standard Switch (VSS) and vSphere Distributed Switch (vDS) and even has a chapter on the Cisco 1000v. One of the really useful parts of the book are the lab examples and designs, which takes you though the design process and considerations to get to the solution.


Definit authors awarded vExpert 2014

Posted by Simon Eady

vExpertIt was with great honor both Sam and I were awarded vExpert 2014 (my first and Sam's second award!) we are both proud to be listed alongside so many others in the vExpert programme.

You can view the announcement and the full list here -


Some useful vSphere related diagrams

Posted by Simon Eady

VMware.jpgOne of the things that never fails to amaze me are the superb PDF diagrams I occasionally stumble upon so i thought it would be a useful idea to list some of the the ones I have found on my travels.

VMware vSphere 5 Memory Management and Monitoring diagram








Concepts and best practices in Resource Pools









Path Selection Policies after removing PernixData

Posted by Simon Eady

pernixdataRecently I have had the pleasure to use PernixData but I did come across a bit of a 'gotcha' after uninstalling it from my hosts.

If like me you use iSCSI then you will likely spend a bit of time setting up your Path Selection Polices to suit your specific needs, so it was interesting to note the following.

When you do uninstall and remove PernixData from your hosts your Path Selection Polices do not revert back to your original configuration rather they revert back to the default vSphere setting of MRU (Most recently used).

This is worth noting as this is not mentioned in the documentation PernixData provide.

UPDATE - After being contacted by the guys at PernixData I can confirm they will be updating their documentation shortly to reflect this outcome.


Extending a vCenter Orchestrator (vCO) Workflow with ForEach – Backing up all ESXi hosts in a Cluster

Posted by Sam McGeown

vCenter Orchestrator (vCO)In my previous post Backing up ESXi 5.5 host configurations with vCenter Orchestrator (vCO) – Workflow design walkthrough I showed how to create a workflow to back up host configurations, but it was limited to one host at a time. For this post I’m going to show how to create a new workflow that calls the previous one on multiple hosts using a ForEach loop to run it against each one. This was actually easier than I had anticipated (having read posts on previous versions of vCO that involved created the loops manually).

Ready? Here we go…

Create a new workflow – I’ve called mine “DefinIT-Backup-ESXi-Config-Cluster” and open the Schema view. Drag a “ForEach” element onto the workflow and the Chooser window pops up. This is a bit deceptive at first because it’s blank! However, if you enter some search text it will bring up existing workflows, so I searched for my “DefinIT-Backup-ESXi-Config” workflow that was created in that previous post.

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