Defensive Computing

USB Flash drives are great. Securing them, however, is not so great. They are easily lost and the more you use one, the more likely it will contain files you consider sensitive. Corsair recently came out with a product that takes an entirely new approach to securing flash drives.

Seeing as this is a Defensive Computing blog, it goes without saying that my personal flash drives are secure. I use a free, open-source program called TrueCrypt. There are however, three problems with this approach:

1. The hassle of installing TrueCrypt and learning how to use it. There is a portable version of it, which I use, but TrueCrypt is a large program with many features (the manual is more than 100 pages) and may be just too much for some people.
2. TrueCrypt only works if you are logged on to Windows as an administrative class user.
3. There is no Mac version (there is a Linux version).

My first approach to security was worse. I bought secure flash drives, models that came with their own security software preinstalled. The secure models cost more than their insecure siblings and the software from each vendor worked differently. At least TrueCrypt gave me a personal standard.

The new Corsair Flash Padlock replaces software with buttons. The side of the device has five buttons with numbers on them, and you press the buttons to chose a password initially and then to enter it later.

I have not used a Flash Padlock, but Scot Finnie wrote a review just a few days ago in his aptly named newsletter, Scot's Newsletter. There can be a huge gap between a good idea and good product. According to Scot, the Flash Padlock is a good product.

For one thing, it's designed to be locked and unlocked without any involvement from a computer. And there are lights that clearly indicate whether it is locked or not. Perhaps most importantly, Scot says "The user interface for the Flash Padlock is very well thought out." If you ever carry sensitive files on a flash drive, read Scot's review.

On the other hand, if you can live with the restrictions of TrueCrypt, then see this getting started cheat sheet that Gina Trapani did in June of last year. Geek to Live: Encrypt your data

If we could only settle on a name for these thingies.

Update: October 3, 2007. Scot wrote a follow-up to his review of the Corsair Flash Padlock drive which notes that the case can be unscrewed to provide access to the un-encrypted flash ram, which sort of defeats the high security. In addition he notes that the encryption software on the Lexar JumpDrive supports Macs despite the fact that the documentation doesn't say so. Finally, he mentions the IronKey flash drive which is very secure and very expensive.

Everyone knows to use a surge protector for their computer. But which one? How do you choose? Welcome to surge protector school.

As their name implies, surge protectors prevent voltage spikes from entering a computer (or whatever else is plugged into them). They are available in a variety of types and, to paraphrase the manual that came with a Dell server, usually provide a level of protection commensurate with the cost of the device. In other words, you get what you pay for.

A surge protector is not a power strip, although a low end model may look like a power strip. Power strips are just extension cords and won't protect a computer from power surges. If it doesn't say "Surge Suppressor," it is probably just a power strip. You can also judge by the price, power strips are cheaper than surge suppressors. A device with no Joules rating is a power strip.

There are many features that go into making a good surge protector.

To begin with, electrical surges can happen on any wire. Thus, you need a surge protector that protects every wire going into your computer. This includes the phone line, if you use dial-up or DSL, and Ethernet network cables, if the computer is on a LAN. Lower end surge protectors only protect the electrical outlet; to get Ethernet or phone line protection, expect to pay a bit more. As a starting point, expect to pay from $20 to $35 for a surge protector.

Have you ever blown a fuse? Some surge protectors work like fuses, and when they absorb all the electricity they can, they die. They may die either from a single big surge or from absorbing many small surges over a long period of time.

What then?

Most likely, a dead surge protector will indicate the fact that it is no longer protecting your equipment with some type of indicator light. However, months after installing it, will you know what the light means? You may not even see it, if the surge protector is behind furniture.

When the surge suppression no longer functions, some surge protectors will continue to provide electricity to the devices. Better models cut off the juice, which protects your devices and makes sure you know to replace the surge protector. Never use a surge protector that provides unprotected power! The last time I checked, the current models of both APC and Tripp Lite would never provide unprotected power to your devices.

You may be thinking that fuses have been replaced by circuit breakers. When there is an overload, a circuit breaker trips and you can easily switch it back later without having to go to the hardware store and buy a new fuse.

Better surge protectors work this way, too. These models are designed to cut off power in a surge rather than absorb it. As a result, they should not wear out over time. There will be a little button that pops out, and you can pop it back in after the surge.

How can you tell if a particular surge protector works like a fuse or circuit breaker? One hint is the warranty, if it has a lifetime warranty then it probably works like a circuit breaker. I suggest only purchasing a surge protector with a lifetime warranty. In general, both APC and Tripp Lite surge protectors have lifetime warranties.

Next up, clamping speed and let-through voltage.

In the July 12th edition of the Wall Street Journal, Walter Mossberg reviewed two new laptop computers, the Dell M1330 and the Toshiba Portege R500. In describing the R500 he said:

"The screen is lit by LEDs instead of by traditional lamps.
That makes for more brightness and saves power."

Raise your hand if you are familiar with the use of LEDs as a light source in laptop computers.

I don't see many hands. Mine isn't raised either.

They seem to be getting popular, just last month Apple started selling their first laptop computer with LED backlighting. The Sony VAIO TX line of laptops uses LEDs as does their TZ line, due to be released very soon. Sony too, claims that LEDs offer increased brightness and decreased power consumption. In addition, they claim that their LED lit screen offers better colors.

Can LEDs really make laptop screens brighter, consume less power and offer better colors?

For those of us who didn't raise our hands, I turned to screen and monitor expert Alfred Poor for advice. For more than 20 years Alfred wrote for PC Magazine, and was their first Lead Analyst for Business Displays. He is a member of the Society for Information Display and the editor and publisher of HDTV Almanac, a web site with news and commentary about HDTV and related topics.

Starting at the beginning, Alfred explained that the liquid crystals in an LCD panel/monitor don't emit light themselves [insert your own dilithium joke here]. Rather "the molecules move in response to electrical fields, and are used as a shutter to block the light." I was surprised how inefficient the technology is. An LCD screen blocks 95% of the backlight, even when it's showing a full white screen.

Traditionally, Alfred said, the backlight source behind the crystals have been cold-cathode fluorescent lamps (CCFL). The use of LEDs in laptop screens is relatively new. According to Alfred, LEDs "already are commonplace in mobile devices such as GPS receivers, cell phones, and PDAs ... the first desktop monitors probably appeared within the past couple of years. Sony had an LCD TV with LED backlights a couple of years ago. I expect that laptops were the last to get the technology."

Cost

Since none of the companies offering LED backlit screens said anything about cost, it's reasonable to assume that LEDs are more expensive than CCFLs.

The M1330 comes with either a CCFL or LED lit screen, so it makes for a handy comparison of the two technologies. The M1330 costs $150 more with the LED lit screen.

With Sony, Toshiba and Apple, the cost of the LED screen is a hidden component of the total price. But these machines aren't cheap. As of July 22nd, the least expensive pre-configured Toshiba Portege R500 was $1,999 and the Sony TZ line started at $2,199.99 (think of it as $2,200). The 15.4 inch Macbook Pro started at $1,999.

Thin and Light

Toshiba claims that in one configuration the Portege R500 is "...the world's thinnest widescreen 12.1 inch notebook PC with an integrated DVD-SuperMulti drive..." Dell claims their M1330 laptop with the optional LED screen is the thinnest laptop computer equipped with a 13.3 inch screen. The Sony VAIO TZ machines are less than an inch thick, but only if measured at the narrowest point. At the highest point, they are 1.17 inches.

Alfred confirmed that LEDs are indeed thinner and therefore the screens can be made thinner. And, they weigh less than cold-cathode fluorescent lamps.

We can see this in the M1330. According to Dell, the LED display "starts at 3.97lbs and is 0.87 inches thick compared to the standard display which starts at 4.28lbs and is 0.97 inches thick." The difference in weight and thickness seem, to me, to be small, but, I suppose if you frequently carry a laptop computer, then perhaps every little bit helps.

Power

Mr. Mossberg gives the impression that by their very nature LEDs save power. Not true, according to our expert. Alfred pointed out that "At present LEDs generally draw more power and produce more heat than CCFL designs." Heat is a problem for all personal computers. It's more of an issue with laptops and still more important in ultraportable models where everything is so closely packed together.

So what is the basis for the claimed power savings? It turns out that the number of LEDs in a screen varies. If the number is low enough, less power is needed and less heat is generated. With a small enough number of LEDs, Alfred said you can "probably save power compared with a CCFL design. This can be used to give either a longer battery life, or to reduce the battery weight and thus get a lighter weight design overall."

I couldn't find anything from Sony, Toshiba or Apple about the number of LEDs in their screens. But in describing the M1330 Dell says "Our optional LED display uses 32 tiny, white LEDs ..." According to Alfred, "32 is a relatively high number for a small screen. Some large HDTV panels using high brightness LEDs could use that count or less for a panel with 8 or 10 times the surface area."

So, if the relatively high number of LEDs means increased heat and no power savings, why does Dell use so many? Alfred explains that LED screens "need a sophisticated lightpipe and diffuser to spread the light evenly behind the LCD panel. The fewer LEDs you use, the more difficult the diffusion process becomes."

Brightness

As to whether LEDs are brighter, Toshiba claims this is true, but offers no specific numbers. Sony claims "incredibly high brightness levels" and the specs for the screen list it at 11.1 candelas (trust me, you don't want to know the exact definition of a candela). The point is that Sony does not offer the candela ratings for their CCFL screens as a point of comparison.

The owners manual for the Dell M1330 shows the LED panel to be 36% brighter than the CCFL panel. Specifically the luminance of the LED screen is 300 cd/m² vs. 220 cd/m² for CCFL (and no, I can't explain what cd/m² means).

Better Color

Sony is the most aggressive in making claims about the better colors in their LED screens, using the terms "brilliant", "amplified" and "true-to-life" to describe them. Toshiba says that indoors, "the LED backlit display produces rich color saturation." I couldn't find anything from Dell that mentioned better colors. Alfred said it is possible that "LEDs can offer better color than CCFL, though advances in CCFL phosphor technology are rapidly diminishing this advantage."

Glossy vs. Matte finish

LED backlighting, being in the back, can be used with screens whose front has either a glossy or matte finish. A glossy screen suffers from glare, but produces more vibrant colors. Each laptop vendor has their own marketing term for glossy screens, Apple is the only company I've seen that actually uses the word glossy. A matte finish may be described as anti-glare or anti-reflective.

The Sony TX and TZ laptops have a matte finish. At the Apple online store you can chose either a glossy or matte finish when you order the 15 inch LED backlit Macbook Pro. I can't be sure about the other laptops because the claims of better colors could be either based on the LED backlighting or the glossy screen or both.

Lifespan

I didn't see any marketing material from a laptop manufacturer that mentioned the expected lifespan of LEDs vs. CCFLs. But, a company that manufacturers LEDs did claim they last longer than CCFLs. When I ran this by Alfred, he said:

The difference is probably not important, but yes, CCFLs don't last as long. Even more significant is that their output decreases over time. End of life is when they are half as bright. LEDs are solid state devices, and "fall off the cliff" in failure mode; in other words, they keep working like when they were new until they stop working. Most people aren't going to keep their notebooks long enough for the CCFL aging to show any difference.

Market Share

Alfred estimates the market share of LEDs at less than five percent, but he expects them to become more common as costs come down. DigiTimes reports that laptop and panel vendors expect that LEDs will be used in about 7% of laptop screens next year (See Nearly 100% of 10-inch-and-smaller LCD panels using LED backlight by Susie Pan and Emily Chuang, July 23, 2007). They estimate that LEDs will be used in 3-5% of laptop computers this year.

To date, LEDs have been popular mostly in smaller displays. In part this is because smaller screens use fewer LEDs which lowers the price differential over CCFL. The DigiTimes article reports that most LCD screens 10 inches and under use LED backlighting. The Sony TX and TZ screens are 11.1 inches, the Toshiba R500 screen is 12.1 inches and the Dell M1330 LED screen is 13.3 inches. The Apple Macbook Pro has the only available 15 inch screen using LEDs, but Apple appears to be having supply problems with them.

Alfred also mentioned that "environmental concerns about heavy metals in the CCFLs" may help to popularize LEDs. Apple seems to be the only laptop vendor using environmental concerns in their marketing. They tout their LED lit screens as being "mercury-free" and the company has long term plans to eliminate mercury from all their products.

Finally, I wondered why Dell and Sony mentioned that the LEDs they use are white. Alfred pointed out that some LED backlights use red, green, and blue, and mix the colors in the diffuser. I didn't bother asking what a diffuser is.

Note: You can hear both Alfred Poor and myself, weekly, on the Personal Computer Radio Show. The show hosts, Joe King and Hank Kee, have been broadcasting out of WBAI in New York City for the last 23 years.

Update July 29, 2007: Updated with a direct comparison between the brightness rating of the two screens offered by Dell for the M1330 (from the Owners Manual).

Recently someone brought me a non-functional laptop computer. The problem turned out to be a dead hard disk. As far as I could tell, the platters inside weren't even spinning.

The laptop owner needed the machine fixed as soon as possible, so he went to the local Best Buy with a printout I gave him from the Best Buy web site for a particular hard disk model. I had reviewed all the laptop hard drives in stock in that particular store and chose one with a low capacity, as his needs were modest, and a long warranty.

Despite the claims of the web site, Best Buy did not have that particular hard drive in stock.

The salesperson suggested another hard drive, priced a couple dollars above the original one. Can you guess where this story is going? Hint: the computer in question was about four years old.

Best Buy sold him a SATA hard drive.

Until recently all hard drives in personal computers used an IDE (also known as ATA) connection to the motherboard. Servers often used a SCSI connection, but IDE was the standard for personal computers. In the last year or two, the new SATA connection standard has become very popular.

The Best Buy salesperson didn't bother looking at the hard drive I suggested to see if it was IDE or SATA. They didn't bother asking how old the laptop computer was. Anyone selling hard drives for computers should know to ask if the computer accepts IDE or SATA. And any four year old laptop is using IDE.

My previous posting (Don't get burned by RAID Zero) on RAID Level Zero was a warning - both that it can be dangerous and that you may inadvertently be using it.

To make an analogy, consider the old joke regarding the purchase of a yacht. The potential buyer asks how much the yacht costs and the seller responds "If you have to ask, you can't afford it." In the current context: if you don't know what RAID Zero is, you shouldn't be using it.

But, the devil is in the details.

The danger with Raid Zero lies in the fact that every file is split between two hard disks and if either fails, you lose all your data. Thus, despite some reader comments to the first posting, your odds of being victimized by a hard disk failure are twice those of someone using a single hard disk. Like a lottery drawing, you have two balls in the hopper.

The hardware device that keeps track of where to store each half of a file is called a controller. If this controller fails, you again lose all your data, even though each hard disk may be alive and well. Your data is there, but without a road map, it can't be found.

A reader disagreed, saying that a Raid Zero controller can simply be swapped out for a new one and your data is not lost. This is not the case.

For one, external hard drives, whether they have one or two internal disks, are not meant to be user serviced. And, it turns out all Raid Level Zero controllers are not the same.

Ontrack Data Recovery

For help with the issue of replacing a RAID Zero controller, I turned to a company famous for being world class experts in hard disks - Ontrack Data Recovery.

If you are not familiar with them, Ontrack is a vendor of last resort. That is, when all else fails and you absolutely must recover the files on a malfunctioning hard disk, call Ontrack. And, to repeat the joke above, if you have to ask how much their services cost, you're data files are not that important.

Jeff Pederson, Manager of Data Recovery Operations for Ontrack Data Recovery, weighed in on the issue of replacing one RAID Zero controller with another:

It's fair to say, that if the RAID Zero controller fails, you're in deep trouble.

This is in stark contrast to hard disks connected to normal ordinary controllers, be they IDE/ATA or SATA. These controllers do indeed all function in the same way and, should one fail, it's a fairly simple thing to connect a hard disk to another one.

Scott Meuller

In the original posting, I mentioned a failed LaCie external hard drive with two internal hard disks, configured as RAID Zero. This was the first time I'd run across an external hard drive, being sold as a single unit (as opposed to a NAS device), with two internal hard disks. Scott Meuller, who was nice enough to add his thoughts on the subject, has been warning people about problems with this design all along (see Got a BIG drive? Then where do you keep the other two?). Quoting:

"... while their designs and shortcomings are obvious to a professional, virtually none of the published product reviews I've seen point out the multiple internal drive/RAID 0 configuration or the potential ramifications."

As for the failure of the RAID Zero controller in one of these units, Scott says it might "be possible to swap the otherwise standard internal drives over to another identical unit in order to restore array functionality (recover the data)."

When it comes to PC hardware, Scott Meuller literally wrote the book on it. Hordes of techies learned the ins and outs of hardware from his line of Upgrading and Repairing PCs books. If he isn't sure how to deal with this problem, it's not one you want to be faced with.

Never mind, that to have an "identical unit", you likely have to have purchased both at the same time.

Other Reader Comments

Many comments on the initial posting mentioned backups as a cure for data loss from a hard disk failure, RAID or no RAID. There will be many postings on this blog in the near future about backing up data on a computer. It's inherent to Defensive Computing.

Thanks to ajhoughton for helping to make my point.

To MC: what is LDO?

Update: July 15, 2007. While browsing the web site of Gateway Computers today, I happened to notice that they offer RAID Zero as an optional feature on the FX530XG computer. Quoting Gateway: "Experience pure power with optional RAID 0 with SATA II/300 drive support for improved performance."

• Original posting: Don't get burned by RAID Zero
• Comments on the original posting

Can't get on the Internet? Can't print to network printer? It's bound to happen sooner or later. Wired Ethernet networks are pretty reliable, wireless ones can be brutally finicky. But no matter what type you're using, it's good to be prepared for networking failures in the future.

When there is a networking problem, the knee jerk reaction may be that there is something wrong with the computer. Perfectly understandable.

But the first step in debugging a networking problem should not involve any of the computers. Rather, you should look at the lights on the box(es) sitting at the hub of the network. The hardware is talking to you and may have something useful to say.

The box(es) may be a number of things. Often there is a broadband modem (cable or DSL) and a separate router. There may even be a third box for VOIP to which a normal telephone is connected. On the other hand, all these functions may be combined in a single box. The advice is the same either way.

Before trouble strikes look at the box(es) holding your network together and make a note of the normal state of every light while the network is functioning properly. Is the light on or off? Green or Amber? Solid or blinking?

So that it's always at hand, I suggest keeping this cheat sheet right next to the device in question. Maybe even tape it to the box, so it can't get lost. Now, when the network fails, the first thing to check is the lights on the box(es).

That's step one. Step two is to examine each box and make a note of the vendor and model number. Then go online to learn what every light can tell you. It's one thing to know that a certain light is normally green, but exactly what does it mean when the light is amber? Or blinking green instead of solid green?

I try to find the manual for the device at the web site of the hardware manufacturer. In addition, I try to find documentation on the lights at the website of the broadband provider. Cable and DSL modems can be modified by an ISP, so their documentation may be more accurate than that from the hardware manufacturer.

If you were given a manual/booklet/pamphlet with the device and can still find it, great. But this would be my last choice for information as it may not be up to date, may cover multiple models or may not reflect customizations made by the ISP.

If, at your ISP's web site, you can't find anything documenting the meaning of each light, then contact your ISP and ask them. Someday, you may be very thankful you did.

To a computer nerd like myself, RAID refers not to a bug spray but to various ways of hooking together multiple hard disks. The various approaches are referred to as levels. Raid levels one through five are designed to decrease the chances that a hard disk failure will result in lost data. Typically RAID configurations are used in server machines as opposed to personal computers.

Raid level zero, however, is the black sheep of the RAID family. It's goal is performance rather than reliability. I'm writing this posting because two of my clients have been burned by their inadvertent use of RAID level zero. Consider this a word to the wise.

Client one purchased an external hard disk from LaCie. This person needed lots of storage space and, at the time, this particular model was top of the line, offering the most storage capacity. The reason it offered more storage than cheaper competing models is that internally there were two 3.5-inch hard disks instead of the usual one. While it looked to the outside world like one chunk of 500 gigabytes, the internal reality was that there were two 250 GB hard disks.

Client two owned a high end Dell XPS tower with two internal hard disks. This person wanted the latest and greatest and fastest computer. Thus, Dell configured the two internal hard disks for speed--RAID level zero. Like the old saying goes, be careful what you wish for, you may get it.

The hard disk is significantly slower than the processor and RAM. Thus to get the fastest read/write performance, RAID level zero stores half of a file on one hard disk and half on the other. Using both hard disks in parallel should reduce the total time needed to write a file.

To someone designing a computer system, the term single point of failure is like kryptonite to Superman. The term refers to a single point in the system which should it fail, would bring down the whole house of cards (so to speak). In an automobile, each tire is a single point of failure, thus they all have a spare in the trunk.

In a personal computer the hard disk is a single point of failure. However, in a RAID level zero configuration, there are three separate single points of failure involving the hard disks. Should either hard disk fail, all is lost because each disk contains half of every file. Oops.

In addition, both of my clients were also dependent on the RAID hard disk controller, the thing with the intelligence to split files as they are written out to the hard disks and re-assemble them back together when read. If the hard disk controller fails, the files may still be alive and well and happy on the hard disks, but you can't read them. Recovering from a RAID level zero controller error might cost thousands of dollars, as its a job for the most sophisticated data recovery companies.

RAID Zero with a failed disk. Click for full-size.

In the case of the client with the Dell computer, it was fairly easy to determine that the problem was with one of the hard disks. Replacing it, re-establishing the Raid zero environment and then restoring a disk image backup got the machine up and running. Disk image backups will be the subject of an upcoming posting on this blog.

The client with the external hard disk lost everything. Not that it mattered, but I couldn't even determine if the problem was with one of the hard disks or the RAID controller.

Update: July 8, 2007. Originally I had said the hard drive was the slowest thing inside the computer, except for the fan. Someone pointed out that optical drives are even slower, so that sentence now says the hard disk is slower than the processor and ram, which was the point I was trying to make.
Note: See the comments on the original posting.

Update: July 13, 2007. See Following up on RAID Level Zero