PLAYING TONIGHT: DRS AND THE IO CONTROLLERS
Ever wondered why the band is always mentioned second, is the band replaceable? Is the sound of the instruments so ambiguous that you can swap out any musician with another? Apparently the front man is the headliner of the show and if he does he job well he will never be forgotten. The people who truly recognize talent are the ones that care about the musicians. They understand that the artist backing the singer create the true sound of the song. And I think this is also the case when it comes to DRS and his supporting act the Storage controllers. Namely SIOC and NETIOC. If you do it right, the combination creates the music in your virtual datacenter, well at least from a resource management perspective. ;)
VCDX- YOU CANNOT ABSTRACT YOUR WAY OUT OF THINGS INDEFINITELY
The amount of abstraction in IT is amazing. Every level in the software and hardware stack attempts to abstract operations and details. And the industry is craving for more. Look at the impact “All Things Software Defined” has on todays datacenter. It touches almost every aspect, from design to operations. The user provides the bare minimum of inputs and the underlying structure automagically tunes itself to a working solution. Brilliant! However sometimes I get the feeling that this level of abstraction becomes an excuse to not understand the underlying technology. As an architect you need to do your due diligence. You need to understand the wheels and cogs that are turning when dialing a specific knob at the abstracted layer. But sometimes it seems that the abstraction level becomes the right to refuse to answer questions. This was always an interesting discussion during a VCDX defense session. When candidates argued that they weren’t aware of the details because other groups were responsible for that design. I tend to disagree What level of abstraction is sufficient? I am in the lucky position to work with PernixData R&D engineers and before that VMware R&D engineers. They tend to go deep, right down to the core of things. Discussing every little step of a process. Is this the necessary level of understanding the applied technology and solutions for an architect? I don’t think so. It’s interesting to know, but on a day-to-day basis you don’t have to understand the function of ceiling when DRS calculates priority levels of recommendations. What is interesting is to understand what happens if you place a virtual machine at the same hierarchical level as a resource pool filled with virtual machines. What is the impact on the service levels of these various entities? Something in the middle might be the NFS series of Josh Odgers. Josh goes in-depth about the technology involved using NFS datastores. Virtual SCSI Hard Drives are presented to virtual machines, even when ESXi is connected to an NFS datastore. How does this impact the integrity of I/O’s? How does the SCSI protocol emulation process affect write ordering and of I/O’s of business critical applications. You as the virtual datacenter architect should be able to discuss the impact of using this technology with application owners. You should understand the potential impact a selected technology has on the various levels throughout the stack and what impact it has on the service it provides. Recently I published a series on databases and what impact their workload characteristics have on storage architecture design. Understanding the position of a solution in the business process allows an architect to design a suitable solution. Lets use the OLTP example. Typically OLTP databases are at the front of the process, customer-facing process, dramatically put they are in the line of fire. When the OLTP database is performing slow or is unavailable it will typically impact revenue-generating processes. This means that latency is a priority but also concurrency and availability. You can then tailor your design to provide the best services to this application. This is just a simplified example, but it shows that you have to understand multiple aspects of the technology. Not just the behavior of a single component. The idea is to get a holistic view and then design your environment to cater the needs of the business, cause that’s why we get hired. Circling back to the abstraction and the power of software defined, I though the post from Bart Heungens was interesting. Bart argues that Software Defined Storage is not the panacea for all storage related challenges. Which is true. Bart illustrates an architecture that is comprised of heterogeneous components. In his example, he illustrates what happens when you combine two servers HP DL380, but from different generations. Different generations primarily noticeable from a storage controller perspective and especially the way software behave. This is interesting on so many levels, and it would be a very interesting discussion if this were a VCDX defense session. SDS abstracts many things, but it still relies on the underlying structure to provide the services. From a VCDX defense perspective, Bart has a constraint. And that is the already available hardware and the requirement to use these different generation hardware in his design. VCDX is not about providing the ideal design, but showing how you deal with constrains, requirements and demonstrating your expertise on technology how it impacts the requested solution. He didn’t solve the problem entirely, but by digging in deeper he managed to squeeze out performance to provide a better architecture to service the customers applications. He states the following:
MS WORD STYLE FORMATTING SHORTCUT KEYS FOR MAC
Recently I started to spend a lot of time in MS word again, and as a stickler for details I dislike a mishmash of font types throughout my document. I spend a lot of time on configuring the styles of the document, yet when I paste something from other documents, MS word tend to ignore these. Correcting the format burns a lot of time and it simply annoys the crap out of me. To avoid this further, I started to dig around to find some font and style related shortcut keys. Yesterday I tweeted the shortcut key to apply the normal style and by the looks of retweets many of you are facing the same challenge. Below is a short list of shortcut keys that I use. There are many more, share the common ones you like to use. As I use Mac I listed the Mac shortcut combination. Replace CTRL for CMD if you are using MS Word on a windows machine. Select text: Select all: CTRL+A Select sentence: CMD + click Select word: Double click Select paragraph: Triple click Formatting: Clear formatting: CTRL+spacebar Apply Normal Style: Shift+CMD+N Header 1: CMD+ALT+1 Header 2: CMD+ALT+2 Header 3: CMD+ALT+3 Change Case: CMD+Option+C (repeat combination to cycle through options) Indent paragraph: CTRL+Shift+M Remove indent: CMD+Shift+M Find and replace: F5
99 CENTS PROMO TO CELEBRATE A MAJOR MILESTONE OF THE VSPHERE CLUSTERING DEEPDIVE SERIES
This week Duncan was looking at the sales numbers of the vSphere Clustering Deep Dive series and he noticed that we hit a major milestone in September. In September 2014 we passed the 45000 copies distributed of the vSphere Clustering Deep Dive. Duncan and I never ever expected this or even dared to dream to hit this milestone. When we first started writing the 4.1 book we had discussions around what to expect from a sales point of view and we placed a bet, I was happy if we sold 100 books, Duncan was more ambitious with 400 books. Needless to say we reset our expectations many times since then… We didn’t really follow it closely in the last 12-18 months, and as today we were discussing a potentially update of the book we figured it was time to look at the numbers again just to get an idea. 45000 copies distributed (ebook + printed) is just remarkable. We’ve noticed that the ebook is still very popular, and decided to do a promo. As of Monday the 13th of October the 5.1 e-book will be available for only $ 0.99 for 72 hours, then after 72 hours the price will go up to $ 3.99 and then after 72 hours it will be back to the normal price. So make sure to get it while it is low priced! Pick it up here on Amazon.com! The only other kindle store we could open the promotion up for was amazon.co.uk, so that is also an option!
DATABASE WORKLOAD CHARACTERISTICS AND THEIR IMPACT ON STORAGE ARCHITECTURE DESIGN – PART 3 - ANCILLARY STRUCTURES FOR TUNING DATABASES
Welcome to part 3 of the Database workload characteristics series. Databases are considered to be one of the biggest I/O consumers in the virtual infrastructure. Database operations and database design are a study upon themselves, but I thought it might be interested to take a small peak underneath the surface of database design land. I turned to our resident Database expert Bala Narasimhan, PernixData’s director of products to provide some insights about the database designs and their I/O preferences. Previous instalments of the series:
DATABASE WORKLOAD CHARACTERISTICS AND THEIR IMPACT ON STORAGE ARCHITECTURE DESIGN – PART 2 - DATA PIPELINES
Welcome to part 2 of the Database workload characteristics series. Databases are considered to be one of the biggest I/O consumers in the virtual infrastructure. Database operations and database design are a study upon themselves, but I thought it might be interested to take a small peak underneath the surface of database design land. I turned to our resident Database expert Bala Narasimhan, PernixData’s director of products to provide some insights about the database designs and their I/O preferences.
DATABASE WORKLOAD CHARACTERISTICS AND THEIR IMPACT ON STORAGE ARCHITECTURE DESIGN - PART 1
Frequently PernixData FVP is used to accelerate databases. Databases are for many a black box solution. Sure we all know they consume resources like there is no tomorrow, but can we make some general statements about database resource consumption from a storage technology perspective? I asked Bala Narasimhan, our director of Products, a couple of questions to get a better understanding about the database operations and how FVP can help to provide the performance the business needs. The reason why I asked Bala about databases is because of his rich background in database technology. After spending some time at HP writing kernel memory management software, he moved to Oracle and was responsible for memory SGA and PGA. One of his proudest achievements was to build the automatic memory management in 10G. He then went on and worked at a startup where he rewrote the open source database, Postgres, to be a scale out, columnar relational databases for data warehousing and analytics. Bala recently recorded a webinar eliminate performance bottlenecks in virtualized Databases. Bala’s twitter account can be found here. As the topic databases is an extensive one, the article is split up into a series of smaller articles, making it more digestible.
IMPROVE PUBLIC SPEAKING BY READING A BOOK?
Although it sounds like an oxymoron I do have the feeling that books about this topic can help you become a better public speaker, or in a matter of fact more skillful in driving home your message. After our talk at VMworld a lot of friends complimented not only on the talk itself but also on the improvements I’ve made when it comes to public speaking. My first public speaking engagement was VMworld 2010 at Vegas, 8 o’clock Monday morning for 1200 people. Talk about a challenge! Since then I have been slowly improving my skills. Last year I’ve done more talks than the previous 3 years before combined. Although Malcolm Gladwell’s 10.000 –hour rule is heavily debated nowadays, I do believe that practice is by far the best way to improve your skill. By itself getting 10.000 hours of public speaking time is rather a challenge and just going through the motions alone will be very inefficient. To maximize efficiency I started to dive into the theory behind public speaking or even more broadly theory about communicating. Over the year I read a decent stack of books but these four stood out the most.
VIRTUAL MACHINES VERSUS CONTAINERS WHO WILL WIN?
Ah round X in the battle between who will win, which technology will prevail and when will the displacement of technology happen. Can we stop with this nonsense, with this everlasting tug-of-war mimicking the characteristics of a schoolyard battle. And I can’t wait to hear these conversations at VMworld. In reality there aren’t that many technologies that completely displaced a prevailing technology. We all remember the birth of the CD and the message of revolutionising music carriers. And in a large way it did, yet still there are many people who prefer to listen to vinyl. Experience the subtle sounds of the medium, giving it more warmth and character. The only solution I can think of that displaced the dominant technology was video disc (DVD & Blue Ray) rendering video tape completely obsolete (VHS/Betamax). There isn’t anybody (well let’s only use the subset Sane people) that prefers a good old VHS tape above a Blue ray tape. The dialog of “Nah let’s leave the blue-ray for what it is, and pop in the VHS tape, cause I like to have that blocky grainy experience" will not happen very often I expect. So in reality most technologies coexist in life. Fast forward to today. Dockers’ popularity put Linux Containers on the map for the majority of the IT population. A lot of people are talking about it and see the merits of leveraging a container instead of using a virtual machine. To me the choice seems to stem from the layer you present and manage your services. If your application is designed to provide high availability and scalability, then a container may be the best fit. If your application doesn’t than place it in a virtual machine and leverage the services provided by the virtual infrastructure. Sure there are many other requirements and constraints to incorporate in your decision tree, but I believe the service availability argument should be one of the first steps. Now the next step is, where do you want to run your container environment? If you are a VMware shop, are you going to invest time and money to expand your IT services with containers or are you going to leverage an online PAAS provider? Introducing an APPS centric solution into an organization that has years of experience in managing Infrastructure centric platforms might require a shift of perspective Just my two cents.
DISABLE VMOTION FOR A SINGLE VM
This question pops up regularly on the VMTN forums and reddit. It’s a viable question but the admins who request this feature usually don’t want Maintenance mode to break or any other feature that helps them to manage large scale environments. When you drill down, you discover that they only want to limit the option of a manual vMotion triggered by an administrator. Instead of configuring complex DRS rules, connect the VM to an unique portgroup or use bus sharing configurations, you just have to add an extra permission to the VM. The key is all about context and permission structures. When executing Maintenance mode the move of a virtual machine is done under a different context (System) then when the VM is manually migrated by the administrator. As vCenter honors the most restrictive rule you can still execute a Maintenance mode operation of a host, while being unable to migrate a specific VM. Here is how you disable vMotion for a single VM via the Webclient: Step 1: Add another Role let’s call it No-vMotion