antipaucity

fighting the lack of good ideas

mtbf – is it really *that* hard?

Most manufacturers will list an MTBF (Mean Time Between Failure) on their products – at least in the computer hardware industry.

A typical number might be 1 000 000 hours. For those keeping track at home, that’s about 114 years! Now, since no harddrive has been running for more than a century, how could they know that?

The important thing to understand is that it is NOT a rating for when the particular drive will fail – but is a statistical representation of the reliability of the entire product line: if you have 1 000 000 hard drives running, each with an MTBF of 1 000 000 hours, then about 1 will fail every hour (I know I simplified the math there). Likewise, if you have 100 000 hard drives*, one will fail about every 10 hours.

So, the next time you’re getting ready to buy a hard drive, by all means check the MTBF – but remember that it doesn’t mean a whole heckuva lot 🙂

Calvin's dad on limits

Calvin's dad on limits

Google has an excellent article (pdf) on this, as well.


*That is a not an improbable number – I have worked with customers *managing* about 50 000 servers, each of which had at least two drives – many with more

1421 by gavin menzies

I enjoy histories – especially when delivered in the format that Gavin Menzies employed in “1421 – The Year China Discovered America”.

The only other history I have read in the past 5 years I can recall reading so fast was Gideon’s Spies.

Gavin makes a compelling presentation, interpretation, application, and conclusion of a host of evidence that seems to indicate that the title is what really happened ~600 years ago, and that it was due to a freak storm and fire in The Forbidden City that the records of the great expedition were destroyed by the emperor’s counterparts in society, the mandarins.

Mr Menzies spent his career as a submariner in the British Navy – a fact which comes up several times during the book, and helps to explain many of the connections he was able to draw when reviewing the historical maps, journals, reports, etc.

1421 is a veritable cornucopia of names and places – European and Chinese explorers, exotic locales (many of which are referenced by the names the various countries used for them), foreign potentates, trade routes, etc. It might behoove one to keep notes when reading this book – or at the very least get used to flipping back and forth to keep track of everyone’s names 🙂

When I bought 1421, I also bought Mr Menzies’ second book, “1434 – The Year a Magnificent Chinese Fleet Sailed to Italy and Ignited the Renaissance”. I can’t wait to read that one to see where his research has led.

  • Quality of writing: 5/5
  • Quality of content: at least 4/5
  • Entertainment value: 4/5
  • Plausibility: 5/5
  • Historicity: likely 5/5
  • Overall: 4.5/5

 

producing your own power by many

Rodale Press published a collected works book entitled “Producing Your Own Power – How to make Nature’s Energy Sources Work for You” in 1974.

There are a host of now-humorous segments of the text:

The US government estimates that by 1980 1 percent of our country’s land will be covered with utility companies’ equipment” {viii}. The contiguous US takes up approximately 1.9 billion acres of land. Do utility companies use 19 million acres? That claim is completely preposterous.

If all mineable fossil resources were made available to us, we would still have energy problems. In a few centuries these would also be exhausted” {ix}. Does the author (Carol Hupping Stoner) of the introduction really believe that in the next few centuries we won’t develop better technologies like we have been for the past thousands of years?

The average six-room, older house probably costs about $400 to $500 per winter to heat” {282}. Based on current heating and cooling costs, how could anyone have afforded to heat their homes 35 years ago? $500 per winter is half what people I know in NY plan to spend every winter now – with a median income of about $60k; 20 years ago, the median was just above $30k (infoplease.com shows slightly different numbers). So 35 years ago folks were spending >5% of their annual income on heating for the winter? That doesn’t grok well.

Other similar claims are made throughout the book with no direct referential backing – merely stating something that the author of that segment wants you to believe. They may have been true. Or not – without references there is no way of knowing where the data came from in the first place. There is a bibliography, but it is only tagged for each segment – there are not direct footnotes/references in the text itself to the original sources.

From having reread this book recently, I think it’s safe to say that the best part of the book is section 3 – Wood Power {pp103-135}. While many improvements have been made in the intervening decades with wood stoves and fireplaces, the information in this chapter on those two heating techniques is still – overall – solid (one of the recommended designs for a fireplace has a tendency to put an unusual amount of smoke into the room if the fire is not kept roaring-hot, but that’s a discussion for another day). Starting on p127 and continuing for 9 pages to p135 is a good discussion on woodlot management, windbreaks, and calculating wood needs for heating purposes.

Personally, I’d alter the suggested woodlot and windbreak designs to include food-producing trees and shrubs in addition to “merely” windbreaking and fuel-producing varieties. If you have the land to grow it – the overriding presumption of most of this book is that you have land – why not make use of the decorative and functional aspects of, say, apple trees? They can provide some privacy, act as a windbreak, and also supply food: just about can’t beat that three-for-one deal!

  • Quality of writing: 2.5/5
  • Quality of content:  2/5
  • Readability: 4/5
  • Overall: 2.5/5

swagbucks?

I’m trying to do some research regarding swagbucks, but so far haven’t found much about them – other than they appear to be legit.

Are they the 2011 incarnation of iWon?

virtualization myth – reduction of servers

Ars Technica has had a great series of articles recently on virtualization (1 2 3 4 5).

But a statement made in part 5 repeated what has been too-often stated as a benefit of virtualization: the reduction of servers, and associated management tasks –

The benefits of performing a large-scale P2V conversion are pretty clear: server consolidation leading to reduced space and power usage and decreased heat output; easier centralized management; new redundancy and high-availability options (including the ability to restore or clone entire VMs at a time); and the opportunity to rebuild the OS of legacy systems, to just name a few. It is very possible to consolidate even a dozen racks’ worth of servers into a single rack, or just two blade chassises. With gains like that, it is no wonder that virtualization is quickly becoming entrenched in the enterprise.

Virtualization does NOT guarantee reduction of servers and management tasks – it can enable the reduction of physical servers in the infrastructure, but because of the ease of spinning-up a new server for testing, development, or just “because”, virtualization has actually lead to a proliferation of servers on the network when they would not have been previously feasible.

If build time is 10 minutes for a VM (typical in environments I have seen/used), then any time someone needs/wants a new server, it can be ready in a few minutes. That’s amazing. The problem is that when it is no longer needed, it needs to be powered-down and have its assigned resources returned to the pool. Sadly, this rarely happens.

There are indeed tools that can help enable this (I was recently trained on one such tool (and, I think, it’s the single best option for the job)), but out-of-the-box, virtualization doesn’t help anything except to reduce the physical footprint of the data center.

applied cryptography, 2d ed by bruce schneier

As recently promised, here is my review of Bruce Schneier’s seminal work, Applied Cryptography (2d edition).

I received my now-signed copy of Applied Cryptography (2d ed) for my 16th birthday – about a year after it was published.

Of all the “odd” books I asked-for when I was younger, this single volume had to take the cake for being both the most expensive, and the least-likely-to-be-read of any.

Bruce Schneier is a world-renowned cryptographer, researcher, and generally Smart Guy™. He has written several other books (many of which I have read (Beyond Fear, Practical Cryptography, Secrets and Lies), and several I own). I also follow on an intermittent basis his blog: schneier.com.

A warning before I go any further – since this book has not been updated in 15+ years, many of the technologies outlined now look incredibly dated or quaint (a 100Mhz processor being “top of the line”, for example). Likewise, measuring computational feasibilities in MIPS-years seems bizarre to me… then again, I’ve never used a MIPS processor.

Back to the book. A lot of time and space is spent on the mathematics and theory behind crypto systems: which is quite cool… except when you don’t understand any of it (as I didn’t a dozen+ years ago [and still don’t to some extent now]). Protocols for a variety of “interesting” activities are discussed: key exchange, digital cash, contract signing, digital signatures, etc.

The most interesting part of the book is the appendix containing C code for several of the algorithms in the book.

Schneier’s writing mixes the highly technical with the amusing (eg p157):

Another biological approach is to use genetically engineered cryptanalytic algae that are capable of performing brute-force attacks against cryptographic algorithms. These organisms would make it possible to construct a distributed machine with more processors because they could cover a larger area. The plaintext/ciphertext pair could be broadcast by satellite. If an organism found the result, it could induce the nearby cells to change color to communicate the solution back to the satellite.

Assume the typical algae cell is the size of a cube 10 microns on a side (this is probably a large estimate), then 1015 of them can fill a cubic meter. Pump them into the ocean and cover 200 square miles (518 square kilometers) of water to a meter deep (you figure out how to do it – I’m just the idea man).

In the intervening time, AES has been adopted as a national standard, replacing DES. We all rely on encryption in daily life on the web (https) when banking, making purchases, or even reading our facebook and twitter accounts. Cryptography has become ubiquitous and invisible to most of us. The product I work most heavily with relies on certificate-based https for all of its internal communication.

In my opinion, this book is still of immense value – though in a different way than it was in the mid 90s: now it’s to serve as a warning about relying on technology and not considering the source, rather than upon how to implement and promulgate that technology.

  • Quality of writing: 4/5
  • Quality of content:  5/5
  • Readability: 3/5 (if you’re unfamiliar with the terminology)
  • Historicity: 5/5
  • Overall: 4/5

 

the personifid project

It’s not often I read Christian fiction – too often some (or even most) the doctrines embraced and promulgated by the authors are not ones I agree with.

I was very pleasantly surprised to fine that R E Bartlett’s book, The Personifid Project was not like that. It’s even a great example of science fiction, in my opinion (wherein my definition of “science fiction” requires the “science” to be plausible inside the world the story creates).

Imagine a world centuries from now where the oceans have evaporated, Man lives in artificially-contained and -supported cities, transportation is automated, and Man has developed the technology to transfer a soul from its original body and place it into an artificial one. That is the world Ms Bartlett creates.

The cover asks an intriguing question, which indeed is why I bought a copy: “when souls reside in artificial bodies.. do they still have free will?”

A huge corporation, Sevig Empire, has created and markets personifids – artificial bodies wherein your soul can reside after discontinuation of your physical body so that humankind can finally escape the eventuality of death. The prime engineering point of the entire technology was a woman named Lavinia (“Lev”), and a man named Ryan. But after a failed transfer of Ryan’s wife, Lev gives-up on the whole enterprise, preferring to die than to be responsible for another failed transfer.

Jump forward 4 years. We meet Aphra who works at Sevig Empire. She has become attached to Ryan in the intervening time since his wife’s discontinuation, but is then unwittingly exposed to a nefarious plot by Sevig (the founder/owner of Sevig Empire) regarding the personifids. In her attempt to escape, she is found and helped by Lev and her husband Birn – Followers of the “Triune Soul” (the future world term for Christians).

Ms Bartlett does a great job of not being preachy about her characters’ faith – but also outlines the basic tenets of Christianity in a way that informs, but does not (or, at least should not) alienate.

In comparison to other science fiction stories I have read, The Personifid Project is similar to Minority Report, I, Robot (the Will Smith film version), Michael Crichton’s Next, and Surrogates – with a little Wall-E thrown-in for the environmental aspects.

  • Quality of writing: 4/5
  • Entertainment value: 5/5
  • Plausibility: 4/5
  • Consistency: 5/5
  • Overall: 4.5/5

I can’t wait to read her second book, The Personifid Invasion.