Got a Question? Contact Me!

December 9, 2012

I have added a contact form to the website to make it easier for people to get in contact with me about things on my blog.

This is to try and stave off the increasing labyrinth of comments that appear to be increasing across my site with questions about the scripts, that are not necessarily related to the blog post itself. Because of this new feature, I will no longer publish comments that are:

a) Not directly related to the post
b) comments to posts older than 2 months.

However, if the questions/comments received are non-trival, I will now include regular Q&A Blog posts to cover the question :)

Thanks for reading :)

Upgrading VMware ESXi with NetApp NFS Storage May Cause VMs to Stop Responding

April 2, 2014

It was supposed to be a routine ESXi upgrade. Having discovered that one of the NetApp's OnTap software had a memory leak which was causing a controller to slow down and eventually fail over every 3-6 months, a pre-requisite of updating the OnTap software was to upgrade the ESXi hosts to at least version 5.

Having been doing a number of these upgrades recently, my confidence was high as I submitted the change requests, notified stakeholders and completed the upgrade.

And then the phone calls started.

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IPv6 Roadshow Wrap

March 11, 2014

Last week I attended the SAGE-AU IPv6 Roadshow that was sponsored by Megaport.

I attended the Hobart event and for someone who has has little to do with IPv6, this event was an excellent introduction. Some of the things I found worthwhile form the event included:

  • How an IPv6 Address is put together and notation rules.
  • Reserved address spaces for IPv6
  • Subnetting a prefix
  • Changes made in the Packet Header compared to IPv4
  • Auto-configuration and Discovery Protocols

There was a lot of in depth information available for those who attended. I think everyone who attended was pleased with the outcomes of the event and hope that SAGE-AU continues to hold more training events like this in the future.

SAGE-AU IPv6 Roadshow

February 18, 2014

IPv6 Roadshow Logo

Have you heard about SAGE-AU‘s National IPv6 Roadshow coming up in March?

SAGE-AU is running a 1 day event around capital cities in Australia to provide IT Professionals an introduction to the new address scheme of the internet and how you would go about implementing IPv6 in your home/business/organisation.

I think many people believe that IPv6 is still a fair way off, and with google reporting some 3% of traffic to it’s site as IPv6, perhaps it is. The problem for those people though is that take-up is accelerating as more networking devices become IPv6 compatible and I think in the next 2-3 years, people will suddenly need to know about IPv6.

To me, it makes perfect sense to get a fundamental knowledge of IPv6 now and be ahead of the game when the protocol hits critical mass.

The IPv6 Roadshow is coming up soon, so if you are thinking about coming, you should register now!

Also, as an IT Professional, you should probably join SAGE-AU and make use of their great benefits.

Disclaimer: I am the 2013-2014 Vice President of SAGE-AU.

HP Releases PowerShell Scripting Tool

November 3, 2013

It would appear that the Practical Admin Blog is read far and wide. This week I got an email from Product Marketing @ HP to let me know that they have released scripting tool for PowerShell recently. Needless to say this is a welcome announcement.

At just on 77,000 lines of code, it quite a substantial libraries of cmdlets, supporting iLO3 and iLO4 devices. In a somewhat strange decision there appears to be no supporting technical documentation linked to the PowerShell scripting tools, unlike the sample scripting tools available for perl & cpqlocfg tools. This has had to leave me delving into the code itself to get an idea what is available.

I am pleased to say that this library of cmdlets appears to have all the functionality my iLO libraries have in the past and would recommend to people have have iLO3 and iLO4 devices to look at this script, or replacing my own scripts with this one.

You can get it from here:

Book Mini Review – The Every Computer Performance Book

August 9, 2013

Shortly after I completed my last post on Dell Performance Monitoring, Bob Wescott contacted me to see if I could mention his book on performance monitoring here. Sure I said, but rather than a a straight-out Ad, I would do a mini review of the book to give my thoughts on it.

I purchased the book The Every Computer Performance Book by Bob Wescott in iTunes for a reasonable price $9.99 AUD. This was after looking at some Sample Chapters that Bob has provided.

The thing that immediately made an impact with me was that this eBook has been written for tablets. It’s not a page-by-page turning book at all, with each chapter being scrollable, and the graphics actually fitting in and around the text unlike many other eBooks I have which started their life in dead tree edition.

The book itself covers many facets of computer performance, including the underlying concepts of performance theory, understanding the tools you are using, how to approach a performance issue which then leads into Performance monitoring, modelling, load testing and capacity planning and finishes up with how to present your results to management.

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Performance Benchmarking Dell R910 – Part 3 (Final)

July 14, 2013

Having covered off on the methodology in Part 1 and the Bare Metal Results of Part 2, we now get onto what was perhaps the more controversial aspect of my testing where I worked – performance under a virtualisation platform. We primarily use VMware, and so the tests were done using this.

Disclaimer: The numbers obtained below are not indicative of the true performance of the server and should not influence any purchasing decisions made. 

With virtualisation, I’m conservative and have a general expectation that I would see some minimal performance degradation of under 10%. The first tests we did consisted of creating an empty VM, and then running the PTS Live CD, as we thought this would rule out any disk I/O operations. I compared the results to the bare metal for each server and was surprised by the results:

Server PTS LiveCD (Bare Metal) PTS LiveCD VM
Dell R910 17000 5400
HP DL380 G5 7000 6105

These results caused great confusion – a roughly 2/3 performance reduction under VMware on the Dell server versus around 1/5 from the HP. Something was amiss. The PGBench results weren’t much better:

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Performance Benchmarking Dell R910 – Part 2

May 16, 2013

Caveats of Benchmarking

Benchmarking is actually something that needs to be considered very carefully and objectively. Not all benchmarks are equal. Phoronix test suite was good in the sense that you can benchmark certain workloads and I chose to focus on apache and PostgreSQL tests in the product as this closely represented the workloads I needed to improve performance on. At this point it was decided to use the PTS Desktop Live ( as it was felt that this test would assure all things would be equal, regardless of platform.

Not everything was exactly equal though – none of the hardware was like for like in specifications. As I was working towards matching and improving the score of the R910 against the DL380 G5, the best I could achieve was to ensure that benchmarks were consistent. In this case the Live CD achieved this by ensuring that the same linux build and benchmarking tools were being used. I will discuss additional factors impacting the results as I continue through this series.

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