The Foolish Things We Do With Our Computers
By Ben Okopnik
"Foolish Things" is a now-and-again compilation that we run based on our readers' input; once we have several of them assembled in one place, we get to share them with all of you. If you enjoy reading these cautionary tales of woe, proud stories of triumph, and just plain weird and fun things that happen between humans and silicon, that's great; if you have some to share so that others may enjoy them, even better. Please send them to articles@linuxgazette.net. [ You can even tell us that it happened to A Friend of Yours, and we'll believe you. ]
-- Ben
Washing Away Your Sins
from Brian Duhan
localLINUX, inc.
My friend Raj assembled a new computer a couple of years ago and he still had its mid-tower case laying down on his workbench. While the machine was on and running he spilled an entire glass of water on the inside. Luckily he realized what had happened and used his lighting fast reflexes (learned from hours and hours of video games) to switch off his power strip almost immediately after the accident. The contents of the glass hit the motherboard at about the same time as he was able to turn it off. After a good drying out, the machine works fine and he sold it to me a few months later (he was going to study for the MCAT; wanted to get rid of distractions). Since then it has been my main machine and regularly stays on for months at a time under heavy load.
A Bolt Out Of The Blue
from Lou Mariotti
A1A Internet Cafe
Rule #1: Women rule this world
Rule #2: Refer to rule 1
Slipping Between Two Electrons
from Ben Okopnik
A number of years ago, I was teaching a computer repair class in St. Louis, and ran across a very nasty problem. At that time, Compaq was using some sort of boot manager that did strange things to the Master Boot Record on their proprietary (read "expensive") drives. The last day of the class was when the students actually got to test and repair their machines (I would gently "break" them in various ways during lunch. :) The problem was a result of several factors:
- It turned out that the computer was infected with the 'Stoned' virus (unsurprising in a rented PC);
- 'Stoned' modifies the aforementioned MBR to execute itself and then the boot code - and stores its own code several sectors after the MBR;
- The student, being a clever fellow who had listened when I talked about boot sector virus removal, deleted the virus code and rewrote the MBR...
- ...which made this Compaq - and as I found out later, any Compaq in a similar scenario - respond with a "Track 0 bad" error.
End of set, end of match, end of game; virus: 1, computer techies: 0. "Track 0 bad" is almost always a hardware-caused error, one which means that track 0 - which is the only place where the MBR can live - is damaged, and the drive is unusable. In this case, I knew better - but the computer did not, and (of course) refused to recognize the drive.
By this point, all my students had clustered around this poor dead beast and were looking at me with that "say, aren't you the expert?" look in their eyes. Ummm, yeah... only the expert had never seen a software-caused "Track 0" error before (nor, other than Compaqs with that exact problem, ever again - thanks to the Universe for small favors.)
I tried using Norton DiskEdit, which had pulled my fat from the fire before. It could see the drive despite what the BIOS said, halleluja!... but only in "read" mode - even the "/M" (maintenance mode) switch didn't help. I had the original MBR backed up onto a floppy, but couldn't write it back. What I needed was for the computer to read a good MBR from the HD - at which point I would be able to put the original MBR back on. It was a Catch-22 problem, in the classic manner.
The solution was simple - and simply horrible... but it worked (the students applauded, at the end.) I took an identical but working drive out of a similar Compaq - there was only one more in the room - booted the machine with it, and then, while power was still on, unplugged it and plugged in the "bad" drive. I was being ultra-careful to not 'stutter' when making or breaking the connections - the last thing I wanted to see was a spark! - and I somehow made it, with both drives and the motherboard surviving the experience (one of my students said that I must have "slipped in between two electrons".) The machine now "knew" that it had a good drive, and I was able to rewrite the MBR.
As a side note, I later found out that the Western Digital low-level format application would wipe the drive clean even though the BIOS didn't recognize it, which would also have fixed the problem (not that I had one with me at the time, but this solution was far less risky.) I also met several repair techs who had thrown away Compaq HDs exhibiting that "Track 0 bad" error. When I told them about my experience, they inevitable cursed up a storm; IDE hard drives were then brand-new on the market and very expensive.
Chillin' Under The Hood
from Heather "Editor Gal" Stern
Linux is cool. FreeBSD is cool. Suns run a little toastier than PCs, but Sparcs are cool.
Unfortunately, when your server closet really is a converted coat closet, it doesn't really matter whether you favor PCs or Sparcs. They do not run cool when they are packed tightly in bread racks. I do mean literal bread racks - purchased a lot more cheaply from restaurant supply than the local rackmount shop, or stores specializing in storage solutions. Is that hum I felt in the metal of the bread rack really supposed to be there? No, I suspect not. Is it from induction by the monitors' electromagnetism, or simply static from the waves of heat warming up this room? It doesn't matter - I recommend wearing light gloves when working in here.
But packing your systems a bit too tightly, while foolish, is just not enough of a Foolish Thing to write home about. In such a closet as I have described, what does seem foolish - now - is what I did when what little that passed for air conditioning finally gave out. The office manager had called for maintenance, but it was going to be several days before they would come to clean and repair vents that should have been replaced years ago.
There really was *some* clearance. The air conditioning was barely useful anyway; I figure its best use was air cirulation. The room had a little table (with yet another computer and monitor on it) and a little bit of clearance for the sysadmin's chair. So I propped it just so, and placed a standard household "box" fan on the chair against this table, pointed at the rack. That helped... a little. It was now possible to stand behind the bread rack to work on cords without having sweat pour off of you.
I thought a good blast of cold from the fridge would do me well, right about then. And I remembered... we have a brick of Blue Ice cooling in the fridge, from someone's lunchbox. I am not going to be so rude as to steal the brick that cools someone's lunchbox. But what an idea...
For those of you not familiar with it, "Blue Ice" is thr brand name for a semi-liquid gel sold in a plastic brick, which can be placed in a cooler where you might place a small brick of ice, however (1) it weighs less and (2) it stays in its plastic container. It swells a little but not a huge amount when frozen. It takes hours to thaw. It was perfect.
So I bought two of these marvels of modern science at the grocery across the street during lunch, and by late afternoon the server closet was essentially swamp-cooled, by having air circulate past a cool blue brick and fed past the otherwise sweltering servers. Because of the swelling we could tell when to swap the brick for the one in the freezer. It lasted okay enough for overnights; the servers survived until maintenance came by.
P.S. Don't forget to wipe the Blue Ice down with a towel before you put it in or take it out of the freezer, unless you also want the humidity of the Florida Everglades to go with the jungle temperature.
Ben was born in Moscow, Russia in 1962. He became interested in electricity
at age six, promptly demonstrated it by sticking a fork into a socket and
starting a fire, and has been falling down technological mineshafts ever
since. He has been working with computers since the Elder Days, when they
had to be built by soldering parts onto printed circuit boards and programs
had to fit into 4k of memory. He would gladly pay good money to any
psychologist who can cure him of the recurrent nightmares.
His subsequent experiences include creating software in nearly a dozen
languages, network and database maintenance during the approach of a
hurricane, and writing articles for publications ranging from sailing
magazines to technological journals. After a seven-year Atlantic/Caribbean
cruise under sail and passages up and down the East coast of the US, he is
currently anchored in St. Augustine, Florida. He works as a technical
instructor for Sun Microsystems and a private Open Source consultant/Web
developer. His current set of hobbies includes flying, yoga, 18th century
reenactment, blacksmithing, sea-shanty singing, and writing; his Palm Pilot
is crammed full of alarms, many of which contain exclamation points.
He has been working with Linux since 1997, and credits it with his complete
loss of interest in waging nuclear warfare on parts of the Pacific Northwest.
Ben is the Editor-in-Chief for Linux Gazette and a member of The Answer Gang.
