Archive
#Nutanix – the ultimate Virtual Computing Platform for VDI – CBRC-like Functionality For Any #VDI Solution with #Nutanix – #IaaS – via @andreleibovici
It’s really great to see the capabilities of the Nutanix platform! Just read this great blog post by @andreleibovici around Content Based Read Cache (CBRC) and how this isn’t necessary at all on a platform like Nutanix!
Conclusion
Overtime I will discuss more about the technology behind Content and Extent Caches. For now what is important to know is that Nutanix provides a better in-memory microsecond latency benefits provided by CBRC for any VDI solution on any of the aforementioned hypervizors, for both Linked and Full-Clones. In fact, Nutanix engineers even recommend Horizon View administrators to disable CBRC because the Nutanix approach is less costly to the overall infrastructure.
It is amazing when your world turns upside down and a technology that used to be awesome becomes mostly irrelevant. It amazes me how fast technology evolves and help organizations to achieve better performance and lower OPEX.
For a long time I have discussed the benefits of CBRC (Content Based Read Cache) available with Horizon View 5.1 onwards, allowing Administrators to drastically cut-down on read IO operations, offloading the storage infrastructure and providing greater end-user experience.
Here are few of the blog posts I wrote on CBRC technology: Understanding CBRC (Content Based Read Cache), Understanding CBRC – RecomputeDigest Method, Sizing for VMware View Storage Accelerator (CBRC), View Storage Accelerator Performance Benchmark, CBRC and Local Mode in VMware View 5.1, View Storage Accelerator (CBRC) Hashing Function.
CBRC helps to address some of the performance bottlenecks and the increase of storage cost for VDI. CBRC is a 100% host-based RAM-Based caching solution that helps to reduce read IOs issued to the storage subsystem and thus improves scalability of the storage subsystem while being completely transparent to the guest OS. However, CBRC comes at a cost.
When the View Storage Accelerator feature (CBRC) is enabled, a per-VMDK digest file is created to store hash information about the VMDK blocks. The estimated size of each digest file is roughly:
- 5 MB per GB of the VMDK size [hash-collision detection turned-off (Default)]
- 12 MB per GB of the VMDK size [hash-collision detection turned-on]
The digest file creation for a large replica disk can take a large amount of time and a bulky quantity of IOPS, therefore it’s is recommendable not to run the operation, create new desktop pools, or recompose existing pools during production hours.
CBRC also uses a RAM to manage the cached disk blocks. The per-VMDK digest file is also loaded into memory. That is the reason why CBRC should not be enabled under memory-overcommit environments. If a host is memory over-committed and CBRC is enabled – the memory pressure is increased as CBRC also uses memory for the cache. In such cases, the host could experience increased swapping and the overall host performance could be impacted.
Whilst I wrote about CBRC benefits, I also received numerous negative comments about the technology, including lack of support for full-clone desktops, being unsupported for layering tools like Unidesk, and taking too long to generate new hashes for every replica.
CBRC is a platform feature (vSphere), however it is only enabled and available via Horizon View. Other VDI products such as XenDesktop or vWorkspace cannot utilize the feature.
Nutanix suppress the need for CBCR, providing similar functionality to any VDI solution running on top of vSphere, Hyper-V or KVM. Nutanix has a de-duplication engine built into the solution that works real-time for data stored in DRAM and Flash.
Content Cache (Dynamic Read cache) Read more…
#VDI Calculator v5 is Now Available with Major New Features – #IaaS, #Storage, #BYOD via @andreleibovici
This is awesome! Great work by @andreleibovici!
I am happy to announce the General Availability of the new VDI Calculator v5. This new version is the single biggest release since I started delivering the calculator. I have completely re-architected the way the calculator works, allowing multiple types of desktops to be configured in a single calculation for a single solution.
All existing features have been retained and will work in the exact same way you are used to, but you now have the ability to select different options for different types of desktops or desktop pools.
As an example, you may choose Desktop Type 1 to be a ‘student’ desktop using Linked Clones with 10 different pools; conversely you may choose Desktop Type 2 to be a ‘professor’ desktop using Full Clones with 5 individual pools. This new calculator gives you much more granular control over your calculations eliminating repetitive tasks when sizing larger environments.
To enable multi-desktop pool calculations just select ‘-’ and ‘+’ in the top bar menu.
Another additional feature is what I call ‘Ask for Help‘. During the application session when you select the Update option a new screen will show up asking if you would like to be contacted by VDI solutions vendors that can help reduce costs, improve performance or improve manageability of your VDI solution. If you are interested…
Continue reading here!
//Richard
Why huge IaaS/PaaS/DaaS providers don’t use Dell and HP, and why they can do VDI cheaper than you! – via @brianmadden
Yes, why do people and organisations still think that they can build IaaS/PaaS/DaaS services within their enterprise’s and believe that they will be able to do so with the “same old architecture” and components used before? It’s not going to be comparable to the bigger players that are using newer and more scalable architectures with cheaper components.
Enterprises just don’t have that innovation power that companies like Google, Facebook and Amazon has! And if they do then most of the time they are stuck in their old way of doing things from a service delivery point of view, stopping them from thinking outside of the box though the service delivery organisation isn’t ready for it..
This is a great blog post on this from Brian, great work!!
Last month I wrote that it’s not possible for you to build VDI cheaper than a huge DaaS provider like Amazon can sell it to you. Amazon can literally sell you DaaS and make a profit all for less than it costs you to actually build and operate an equivalent VDI system on your own. (“Equivalent” is the key word there. Some have claimed they can do it cheaper, but they’re achieving that by building in-house systems with lower capabilities than what the DaaS providers offer.)
One of the reasons huge providers can build VDI cheaper than you is because they’re doing it at scale. While we all understand the economics of buying servers by the container instead of by the rack, there’s more to it than that when it comes to huge cloud provider. Their datacenters are not crammed full of HP or Dell’s latest rack mount, blade, or Moonshot servers; rather, they’re stacked floor-to-ceiling with heaps of circuit boards you’d hardly recognize as “servers” at all.
Building Amazon’s, Google’s, and Facebook’s “servers”
For most corporate datacenters, rack-mounted servers from vendors like Dell and HP make sense. They’re efficient in that they’re modular, manageable, and interchangeable. If you take the top cover off a 1U server, it looks like everything is packed in there. On the scale of a few dozen racks managed by IT pros who have a million other things on their mind, these servers work wonderfully!
Free online Computer Science courses from #Harvard College
Ok, this is really interesting (at least for a nerd like myself)!
I just stumbled across this website where the Harvard College hosts some of its courses online, you can view video recording from classes, get access to all slides, source code etc and take the course for free yourself!
They now have the following courses up there;
- Computer Science 50: Introduction to Computer Science I – Introduction to the intellectual enterprises of computer science and the art of programming. This course teaches students how to think algorithmically and solve problems efficiently. Topics include abstraction, algorithms, encapsulation, data structures, databases, memory management, security, software development, virtualization, and websites. Languages include C, PHP, and JavaScript plus SQL, CSS, and HTML. Problem sets inspired by real-world domains of biology, cryptography, finance, forensics, and gaming. Designed for concentrators and non-concentrators alike, with or without prior programming experience.
- Computer Science 164: Mobile Software Engineering – Introduction to principles of software engineering for mobile devices and best practices, including code reviews, source control, and unit tests. Topics include Ajax, encapsulation, event handling, HTTP, memory management, MVC, object-oriented design, and user experience. Languages include HTML5, JavaScript, Objective-C, and PHP. Projects include mobile web apps and native iOS apps.
- Computer Science E1: Understanding Computers and the Internet – This course is all about understanding: understanding what’s going on inside your computer when you flip on the switch, why tech support has you constantly rebooting your computer, how everything you do on the Internet can be watched by others, and how your computer can become infected with a worm just by turning it on. In this course we demystify computers and the Internet, along with their jargon, so that students understand not only what they can do with each but also how it all works and why. Students leave this course armed with a new vocabulary and equipped for further exploration of computers and the Internet. Topics include hardware, software, the Internet, multimedia, security, website development, programming, and dotcoms. Through optional hands-on sections and workshops, local students have opportunities to dissect as well as upgrade a computer with additional hardware, search the Internet more effectively, build a wireless network, create digital images, eradicate spyware, and design webpages. Problem sets offer online students similar opportunities. This course is designed both for those with little, if any, computer experience and for those who use a computer every day.
- Computer Science E76: Building Mobile Applications – Today’s applications are increasingly mobile. Computers are no longer confined to desks and laps but instead live in our pockets and hands. This course teaches students how to build mobile apps for Android and iOS, two of today’s most popular platforms, and how to deploy them in Android Market and the App Store. Students learn how to write native apps for Android using Eclipse and the Android SDK, how to write native apps for iPhones, iPod touches, and iPads using Xcode and the iOS SDK, and how to write web apps for both platforms.
Continue reading and take the courses here!
Happy coding! 😉
//Richard
The IT Melting Pot! 