Learning | The Data Center Overlords

LACP is not Link Aggregation

March 28, 2016 Leave a comment

So there’s a mistake I’ve been making, for years. I’ve referred to what is link aggregation as “LACP”. As in “I’m setting up an LACP between two switches”. While you can certainly set up LACP between to switches, the more correct term for the technology is link aggregation (as defined by the IEEE), and an instance of that is generically called a LAG (Link Aggregation Group). LACP is an optional part of this technology.

Here I am explaining this and more in an 18 minute Youtube video.

Filed under Always Be Learning, Ethernet, Fun Fact, Learning Tagged with 802.1ax, 802.3ad, EtherChannel, LACP, LAG, link aggregation, port channel

Po-tay-to, Po-ta-to: Analogies and NPIV/NPV

May 21, 2012 2 Comments

In a recent post, I took a look at the Fibre Channel subjects of NPIV and NPV, both topics covered in the CCIE Data Center written exam (currently in beta, take yours now, $50!). The post generated a lot of comments. I mean, a lot. Over 50 so far (and still going). An epic battle (although very unInternet-like in that it was very civil and respectful) brewed over how Fibre Channel compares to Ethernet/IP. The comments look like the aftermath of the battle of Wolf 359.

Captain, the analogy regarding squirrels and time travel didn’t survive

One camp, lead by Erik Smith from EMC (who co-wrote the best Fibre Channel book I’ve seen so far, and it’s free), compares the WWPNs to IP addresses, and FCIDs to MAC addresses. Some others, such as Ivan Pepelnjak and myself, compare WWPNs to MAC addresses, and FCIDs to IP addresses. There were many points and counter-points. Valid arguments were made supporting each position. Eventually, people agreed to disagree. So which one is right? They both are.

Wait, what? Two sides can’t be right, not on the Internet!

When comparing Fibre Channel to Ethernet/IP, it’s important to remember that they are different. In fact, significantly different. The only purpose for relating Fibre Channel to Ethernet/IP is for the purpose of relating those who are familiar with Ethernet/IP to the world of Fibre Channel. Many (most? all?) people learn by building associations with known subjects (in our case Ethernet/IP) to lesser known (in this case Fibre Channel) subjects.

Of course, any association includes includes its inherent inaccuracies. We purposefully sacrifice some accuracy in order to attain relatability. Specific details and inaccuracies are glossed over. To some, introducing any inaccuracy is sacrilege. To me, it’s being overly pedantic. Pedantic details are for the expert level. Using pedantic facts as an admonishment of an analogy misses the point entirely. With any analogy, there will always be inaccuracies, and there will always be many analogies to be made.

Personally, I still prefer the WWPN ~= MAC/FC_ID ~= IP approach, and will continue to use it when I teach. But the other approach I believe is completely valid as well. At that point, it’s just a matter of preference. Both roads lead to the same destination, and that is what’s really important.

Learning always happens in layers. Coat after coat is applied, increasing in accuracy and pedantic details as you go along. Analogies is a very useful and effective tool to learn any subject.

Filed under Always Be Learning, CCIE Data Center Prep, Certifications, data center, Ethernet, Fibre Channel, Learning, Storage

The VDI Delusion Book Review

April 14, 2012 1 Comment

Sitting on a beach in Aruba (sorry, I had to rub that one in), I finished Madden & Company’s take on VDI: The VDI Delusion. The book is from the folks at brianmadden.com, a great resource for all things application and desktop delivery-related.

The book title suggests a bit of animosity towards VDI, but that’s not actually how they feel about VDI. Rather, the delusion isn’t regarding the actual technology of VDI, but the hype surrounding it (and the assumption many have that it’s a solve-all solution).

So the book isn’t necessarily anti-VDI, just anti-hype. They like VDI (and state so several times) in certain situations, but in most situations VDI isn’t warranted nor is it beneficial. And they lay out why, as well as the alternative solutions that are similar to VDI (app streaming, OS streaming, etc.).

It’s not a deep-dive technical book, but it really doesn’t need to be. It talks frankly about the general infrastructure issues that come with VDI, as well as delivering other types of desktop services to users across a multitude of organizations.

It’s good for the technical person (such as myself) who deal in an ancillary way with VDI (I’ve dealt with the network and storage aspects, but have never configured a VDI solution), as well as the sales persons and SE that deal with VDI. In that regard, it has a wide audience.

Brian Drew over at Dell I think summed it up the best:

For anyone dealing with VDI (who isn’t totally immersed in the realities of it and similar technologies) this is a must-read. It’s quick and easy, and really gets down to the details.

Filed under Always Be Learning, Learning, VDI, Virtualization

Initial Thoughts on Apple’s New Initiative

January 25, 2012 Leave a comment

When I heard about Apple’s new education initiative, I got excited. For one, it’s Apple. And yes, I’m a fanboy. So, like… Squeeeeeeee.

Tony, you have a problem

But it’s not algebra or geography books geared towards primary education that excites me (although that’s pretty cool), it’s how it could revolutionize IT ebooks.

Right now the primary market for technical books is print books. There are technical eBooks available on a variety of eBook platforms, but for the most part, technical books are a print business, with eBooks as an afterthought.

This approach has worked since the tech industry begain, but it does have its limiations.

For one, tech books usually have a percentage of its content that’s out of date by the time it reaches the shelves. Technical books can take over a year to get from outline to ending up on the shelves, and naturally the fast-paced moves from under the book. And going an update or corrections to a book is a major effort. If it’s C programming, it’s probably not too much of an issue. But a book on FCoE or VXLAN? There’s bound to be lots of changes and corrections within the span of a year.

What do you mean my book on cell phones isn’t current?

Also, eBooks right now are mostly just electronic versions of the paper books (ed: duh). The electronic format could do a whole lot more than just words on page, as shown by Apple in their presentation. With a fully interactive eBook, there could be animations (really awesome for networking flows), interactive quizzes (and huge test banks, not just 10 questions per chapter).

And right now eBooks seem to be an afterthought. Not all physical titles are available in eBook format (hint, several important and influential Fibre Channel books), and the ones that are can seem like a rush job. In my preparation for the CCIE Storage written test, I picked up this ebook on the Kindle platform: CCIE Network Storage. The ebook version was riddled with formatting errors which made it sometimes difficult to follow. Also, it looks like they’ve seem to have even taken it off Kindle.

Right now my favorite eBook format is the Kindle. Despite being an Apple fanboy, Kindle has the largest library of technical books, by far. And Kindle’s reader and cloud storage make managing your library stupid easy. Apple also makes it easier, although the platform is limited to Apple devices, and the tech library doesn’t seem to be as comprehensive. All of this this is in stark contrast to Adobe’s shitty eBook platform, which seems to want to destroy eBooks.

The Controversy

So the controversy is in Apple’s EULA. If you create an iBook with the iBook Author, that “Work” must be distributed through the Apple iBook store if you charge a fee for it. The tricky part is how Apple defines the term “Work”. Right now it’s a bit ambiguous. Some claim that the term “Work” defines the totality of the book. Others (like the Ars article) say “Work” only defines the output of the iBook Author program (PDF of Apple’s proprietary eBook format).

So if I write a book, and create an eBook version of it with Apple’s iBook Author (which looks like it create amazingly interactive ebooks), can I take the material from the book and make a (probably less interactive) Kindle version of the book?

Tony’s Take

Whether you like Apple or not, you have to admit this certainly ups the game. It’s high time eBooks took center stage for technical eBooks, instead of being an afterthought.

Right now the networking and data center landscape is changing fast, and we need new and better ways to cram new knowledge into our brainbags. A good interactive ebook, riddled with animations, audio, and large test banks would certainly go a long way to help. I don’t really care if it’s Apple or Amazon that provide that format. But right now, it looks like Apple is the only one saddling up.

The Data Center Overlords