Yellow Bricks

by Duncan Epping

Various

How thermal paste can impact VM performance

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On twitter a tweet from Frank flew by pointing to an article which was written by one of my VMware colleagues: Matt Bradford aka @VMSpot. I hadn’t seen the article, while it was written in 2014 and I am surprised it never caught more attention. Matt describes in his post how the use and placement of thermal paste can influence VM performance. Who would have thought of that, and I am seriously impressed they managed to get to the bottom of this!

We haven’t had our HP BL460c Gen8’s with the new Xeon E5-2697 v2 12 core processors long. Last week we started to get e-mails from the help desk that users were complaining about sluggish performance in Citrix. Oddly, all of the XenApp VM’s happened to live on the same ESXi host. I say oddly because performance issues rarely seem to fall in line as they did here. We immediately evacuated the host and admitted it to the infirmary cluster.

…..

It didn’t seem to matter if the CPU’s were under load or idle, the temperature would not stray from 69°c. This had to be an issue with the temperature sensors, I thought. So we pulled the host and removed the heat sinks so we could look at the CPU’s through a thermal camera we borrowed from engineering.

I am not going to post the full article here, go over to Matt’s blog and have a read. It is flabbergasting if you ask me, and definitely one of the coolest reads in a long time. And thanks Frank for bringing this one up. I just had to share in on a broader platform.

That reminds me, maybe it is time to bring back my “favourite reads” post I did for a long time on the VMTN Blog, but host it here instead. Hmmm. Ah well, lets make a start here and follow up with “Recommended reads” posts in the future:

That’s it for now, enjoy reading.

Virtually Speaking Podcast: Rubrik and Virtual SAN

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As John Nicholson was on a holiday I got to co-host the Virtually Speaking Podcast together with Pete Flecha. As a guest we had Chris Wahl and we spoke about many different things, but the key theme was Rubrik and the paper Chris and Cormac wrote that talks about Rubrik backing up VMs that sit on top of VSAN. I think it was a fun conversation and just wanted to share it with you here. For those who haven’t listened to Virtually Speaking Podcast yet, make sure to subscribe and catch each episode as they are entertaining and educational at the same time if you ask me!

Goodbye SAN Huggers!

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This week I presented at the German VMUG and a day after the event someone commented on my session. Well not really on my session, but more on my title. My title was “Goodbye SAN Huggers“. Mildly provocative indeed. “SAN Huggers” is a play on the term “Server Hugger“. That term has been around for the longest time and refers to people who prefer to be able to point out their servers. People who prefer the physical world, where every application ran on one server and every server was equal to one physical box.

SAN Huggers are pretty much the same type of people. They prefer the physical world. A world where they define RAID Groups, Storage Pools and LUNs. A world where a bunch of servers end up on the LUN they created. Those LUNs have certain data services enabled and if you need other data services, well then you simply move your servers around! SAN Huggers like to maintain strict control, and to me personally they are in the same position the Server Huggers were 12-15 years ago. It is time to let go however!

Now let it be clear, 12-15 years ago when virtualization changed the world of IT and VMware exploded literally and server huggers felt threatened by the rise of virtualization servers did not go away. Server Administrators did not disappear. Server Administrators evolved. Many took on additional responsibilities, in most cases that would be the responsibility over VMware ESX / Virtual Infrastructure. The same applies to storage.

When I say goodbye SAN Huggers, I am not referring to “Virtual SAN” taking over the world. (Although I do think that Hyper-Converged will eat the traditional storage system’s lunch for a large portion.) I am talking about how the world of storage is (and has been) evolving. Literally my next slide typically has a quote on it that states the following: “Hardware evolution started the storage revolution“. The story around this slide makes it clear what I mean when I say Goodbye SAN Huggers.

The hardware evolution has literally changed the storage landscape. Software Defined Storage is quickly taking over the world, but in my opinion the key reason for this is the evolution from a hardware perspective. In the past we had to group harddisk to provide a single unit that could deliver sufficient capacity, performance and increase availability at the same time. That was achieved using RAID constructs, and with the introduction of virtualization and high demanding workloads storage systems had to resort to wide striping, introduced larger caches, disk pools etc to deliver the capabilities required.

In todays world a lot of these constructs are no longer needed. The evolution in the world of hardware allowed for the introduction of Software Defined Storage. First and foremost flash, whether PCIe, NVMe or SAS/SATA based. These devices removed the need for complex constructs to provide thousands of IOPS. A single flash device today, even consumer grade, can provide higher performance than many of the storage systems we have all managed over the years. Not even talking about enterprise grade flash devices where 100k IOPS (with sub millisecond latency) is more or less the norm. Than there is the network, 10GbE, 25GbeE, 40GbE and even higher. Low latency and high bandwidth comes at (relative) low cost, and add to that the ever growing CPU capabilities, cores and speed combined with faster bus speeds and high (and fast) memory configurations. Hardware is no longer a constraint, the revolution is now, enter the world of Software Defined Storage.

And this, this is where I typically introduce: Virtual SAN, Virtual Volumes and the vSphere APIs for IO Filtering (vSphere Data Services delivered through filter drivers). Functionality provided by VMware which enables efficient operations, simplicity and flexibility. All through the use of policy, which can simply be attached to your workloads, be it a virtual machine or virtual disk even. The days of creating LUNs, RAID groups and needing wide striping or huge amounts of devices to get a decent user experience are gone. We can say goodbye to the physical world, we can say goodbye to the SAN Hugger. We can move forward and evolve, not just our datacenters but also our personal growth and areas of interest and expertise as a result.

My Personal Top 10 Albums of All Time

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Yesterday on twitter someone asked me what my personal favourite rock album was, not something I had to think about for long, in that genre there are a couple of bands for me that really stand out. When I replied to the question Christian Mohn responded as well, he had a different album in mind and based on that he wrote an article with his top 10. (Recommended read for sure!) I figured I would go through the same exercise. Not easy considering I listen to many different types of music, and there are many many albums I really like. Just like Christian I looked at some of my play stats, but they don’t necessarily reveal how I feel about an album and partly are also the result of a phase and what is happening around me.

So I sat down and started listing albums, and then started removing albums from the list. I tried to include at least 1 album from every genre I listen to, but with a strong focus on rock / alternative music. Ow, if the youtube link isn’t working in the country you live in there’s not much I can do about it… Also, if you are here purely for technology articles I appreciate that as well, just skip the article.

Here we go.

10. Elvis – If I can Dream (with the Royal Philharmonic Orchestra)
This is where it all started for me, not this particular album, but Elvis in general. My parents were fans, and as they owned a bunch of records it was what I played first on my own record player. Compared to what my friends were listening back then, if they were even listening to anything, it was a bit different… not as “current”. I guess this is where it started for me. This album in particular stands out, it has most of my favourite songs, it was released in 2015. Yes 2015, they recorded new orchestral arrangements and combined that with earlier recorded vocals. It sounds amazing. My favourite song is definitely Bridge Over Troubled Water. (youtube / spotify) [Read more…] about My Personal Top 10 Albums of All Time

How do I get to the next level – Part 2

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I was going over some of the posts of the last year which have had a large number of views and/or comments, just to figure out what interests you folks the most. One of the articles that stood out in terms of number of comments definitely was “How do I get to the next level“. Not just the comments, but I also recall the large number of tweets and feedback I received in person. I just read the article again, and there are a few things which I think I should have probably emphasized more. I figured I would write a follow up… Lets start with a quote from that article.

There is also that thing called “being at the right place, at the right time” and of course seeing opportunities, grabbing opportunities and taking risks.

This phrase was in the first paragraph of the article, and I think it captures a lot more of the essence of success than may seem obvious. A month or so ago I was having a conversation with someone and that person mentioned that in terms of my role within VMware I was lucky to be in the position I am in today. Although I agree that I am very fortunate to have found such a great role, and that there is always luck involved in some shape or form, luck is usually not the reason you are rewarded with a promotion or a new opportunity.

Being at the right place at the right time is one part of it, seeing and grabbing (risky) opportunities is another part. Although you need to be somewhat lucky to have picked the right place and time, one could also argue that it is a skill / talent (like football / hockey players knowing intuitively where the ball / puck will be). Also, don’t worry about failures. Everyone makes mistakes, some pick wrong focus areas, some pick the wrong role or even wrong company to work for, be open and stay alert and assess your position or situation. How is the world (around you) evolving? Is your path leading somewhere? Is this what you expected it to be? Use the information next to make decisions. Do you keep going? Do you need to adapt or even abort and go back to the drawing board?

If I have learned one thing, than it is definitely that I learn the most when I am out of my comfort zone. And if you want to set yourself up for success, you will need to make sure you are capable of adapting fast and learn quick. Learning quick typically happens outside of your comfort zone. Now don’t mistake being out of your comfort zone with being in your panic zone. It is okay to be anxious, to be nervous, to have that jittery feeling… but be aware that this does not turn in to anxiety. Most of you have been in that place at some point in time, you need to do something far far out of your comfort zone, for me that was designing and configuring a network environment (including routing) when I had been responsible for Windows/X86 servers for a couple of years. Way out of my depth for sure back then, which resulted in anxiety and ultimately a failed project. Which leads me to the next skill that will help you grow: Knowing what you know.

But maybe more importantly, knowing what you don’t know and admitting you don’t know. Many people know what they are good/great at, and many will also advertise that broadly. But it is more importantly to understand what your limits and weaknesses are. Knowing that will allow you to understand where you need to grow, and come up with a plan to improve skills / behaviour etc. Also, it will allow you to say “no” when you are out of depth, this is key if you want to set your self up for success, and if you want to grow.

For me personally the one thing that stood out as a weakness (or even lacking skill), when I looked at where I wanted to be and what it would take, was public speaking. I tried it, I failed, no need to pretend, I knew I had to get better at it to grow from a personal perspective, but also from a career standpoint. At a certain level within each organization, presenting is simply required. I was foolish enough to throw myself in at the deep end, my first public speaking experience was at one of the largest conferences (VMworld). That was definitely far outside of my comfort zone and straight in to the panic zone. I should have taken 3 steps back, in hindsight, and started with a small session as a small VMware User Group. Read my article on this, don’t make the same mistake I did… Anxiety doesn’t even come close to describing what I felt. Yes, I did take a step back, reconvened and decided I would never do this again… Well that was my first conclusion. Quickly after that I reached the conclusion that I went too fast, I needed to slow down and take smaller steps. I needed to start with something less nerve wrecking (but still right at the edge of learning and panic zone), which was presenting at a VMUG. Today, I spend most of my time talking to customers or at events, it is safe to say that I have overcome the anxiety. Also, I managed to get really close to where I wanted to be in 3-5 years as a result.

As mentioned in “part 1”, being able to share your thoughts/opinion can make a big difference for your career, whether that is in a meeting / a blog / public speaking is besides the point even. But also speaking up and fighting for something you (strongly) believe in can make a big difference (it did for me). Passion, enthusiasm, energy are all character traits I personally value high and is what I look for when I interview potential candidates. Willingness to take that extra step and go all-in when you believe in something, yet at the same time also know which battle to pick, know when to sit down and listen. That last part is probably the most important, you cannot win them all and you cannot even fight all battles, knowing when to back down is key and an important skill to master. (Is it a skill, or a character trait even?)

Last but not least, perseverance and focus. If you truly want something, focus, make a plan and get things done. Learn from your mistakes and adapt. Don’t be afraid to take a step back and take a different route, even if it will take longer to get where you want to be. As Winston Churchill once said, “Continuous effort, not strength or intelligence, is the key to unlocking our potential.”