Comment On It Doubles as a Saw Horse

W00t!  That's even better than the classic "server gets unplugged every night when the cleaners need to plug in the vacuum" story.

I would say no way, but I know better now.

 

I hope the contractor paid for the drives, and the tech.

 

 

In addition, they should have used hard drives from Milwaukee, Makita, or Black and Decker.  No more pesky vibration problems then!

i love how the contractor didn't put together that every time he used that case as a sawhorse, lots of people came in and had to work on the stuff in that case...


 

Hehehe... I think my brother have worked there!
This WTF is nothing. My brother have machines that can create giganteous clouds of dirt, my earthquake, everything.

--Tei 

 

Ah, a WTF from my alma mater. Go Jackets! :)

Wow. I want to say 'no way', but somehow I can actually believe this. After all, it's not that obvious that you can't brace a workboard against a computer ... well, not if you're a saw monkey that doesn't know the first thing about computers, anyway. The Real WTF is that the contractors were allowed in the same room as the servers, or the other way around, without the two sets of people talking to each other about how to keep computers and buildings both working!

My close friend and former coworker was sent to Hawaii, from New Jersey, because of a deep fat fryer using the same circuit as the computer that ran our software. Files were corrupted every day around 4PM, when they turned the fryer on. This was over 15 years ago. Not much changes.

I wouldn't expect a construction worker (who presumably spends more time hammering and sawing than typing) to understand the damage they are doing to computers/drives/whatever, but I would imaging someone from the university should have been there to make sure this type of thing (as opposed to unplugging the servers to plug in the radio) didn't happen.

 

I just don't buy it.

When you're cutting wood, you're not using a lot of force. You let the tool do the work. You can easily hold the wood in your hands, although doing such a thing would be silly for several reasons (jigglyness, splinters, etc.) Even if you do provide a lot of force for some reason (let's say they climbed on the wood) you'd still be hard-pressed to damage the server. The cases are made out of sheet metal, and they're boxes. People used to put CRT monitors on them ALL THE TIME.

Are the disks outside of their protective dust case? Are they not in the metal case? I have never seen a disk drive just sitting out on a bench waiting for wood to be placed upon it.

In order to force the heads to scratch the platters, then you're going to have to exert force on just the heads. You can't selectively do that when the disks are in their shells, in the server case, in the rack. The only possibility would be if the university's critical server was taped to the top of the case, with its protective dust cap removed in the middle of a construction zone.

What kind of setup is that? I'm going to say it's a "fictional" setup.
 

Boy, it didn't turn out to be some scary coworker who thought he could save cash on the electricity bills by shutting down production servers when no one was working at the console.

themagni:

I just don't buy it.

When you're cutting wood, you're not using a lot of force. You let the tool do the work. You can easily hold the wood in your hands, although doing such a thing would be silly for several reasons (jigglyness, splinters, etc.) Even if you do provide a lot of force for some reason (let's say they climbed on the wood) you'd still be hard-pressed to damage the server. The cases are made out of sheet metal, and they're boxes. People used to put CRT monitors on them ALL THE TIME.

Are the disks outside of their protective dust case? Are they not in the metal case? I have never seen a disk drive just sitting out on a bench waiting for wood to be placed upon it.

In order to force the heads to scratch the platters, then you're going to have to exert force on just the heads. You can't selectively do that when the disks are in their shells, in the server case, in the rack. The only possibility would be if the university's critical server was taped to the top of the case, with its protective dust cap removed in the middle of a construction zone.

What kind of setup is that? I'm going to say it's a "fictional" setup.
 

A saber saw? ir jig saw?  those vibrate ALOT.   I wouldn't try it on my servers.

themagni: obviously you never tried sawing a large wooden board before. The thing vibrates a lot, and if a computer case with disks happens to be on one side of the board (even if it's underneath), I can easily see how the vibrations can damage the disk heads.

themagni:

I just don't buy it.

When you're cutting wood, you're not using a lot of force.

My guess (having worked in construction for a few years) is that the damage was not derived from the actual cutting, but by the way the lumber was tossed onto the "sawhorses".  Rough carpenters don't exactly lay their pieces down gingerly with kid gloves.

 

    Clearly you don't understand the damage vibrations (perhaps those from say...a saw blade cutting through wood) can inflict on sensitive hardware.

You might not be bearing down with a lot of force. But I have had wood vibrate due to the saw motions. So I dont think that its the weight or the dust that caused the damage, but the vibrations could cause the disk heads to hit the platters.


 

themagni:

I just don't buy it.

When you're cutting wood, you're not using a lot of force. You let the tool do the work. You can easily hold the wood in your hands, although doing such a thing would be silly for several reasons (jigglyness, splinters, etc.)

It's comments like this that make construction workers look down on programmers as girly-men.

I have a hint for you: you were pretty close to the reason with the word "jigglyness," although there's another word for it that most people (who aren't girly-men) would use.

But if your using a sabersaw you are going to be putting a tremendous amount of quite high frequency, high amplitude vibrations into a server box. If the drives are for a major server theyre probably spinning very very fast and are not built to withstand that sort of vibration. The drive heads are "free-standing" to a degree and if you hit a resonant tone or just jog them hard enough they can sway the sub-milli-meter distance and smash into the plates.

Not that im saying this actually happened here but its definatley possible, if it required you to "exert force on just the heads" to damage a drive it shouldnt matter what i do with my laptop which is definatley not the case (i went through three drives on one of my laptops).

Damn, 4 people beat me to that, i must be a slow typer.

Anonymous:

Damn, 4 people beat me to that, i must be a slow typer.

I feel the same way.  Guess that was a pretty softball question.  I'm kinda sad no one else went for the "condescending half-flame" method I used. Yall are way too nice.

I wish you were right about this being made up, themagni, but I was there working with John when this was going on.  ISTR it was during the College of Computing's move to the spiffy new dedicated building (that went with the promotion from department to full college), but it might have been an intra-building move later on.  In any case, fact, not fiction.

 I'm surprised that this post wasn't anonymized, though. What's up with that?

 

themagni:

I just don't buy it.

When you're cutting wood, you're not using a lot of force. You let the tool do the work. You can easily hold the wood in your hands, although doing such a thing would be silly for several reasons (jigglyness, splinters, etc.)

Take a look at this demo Skip to about 35 seconds in. See all that stuff jumping around? Imagine that's the inside of your server.

Feel stupid yet?

zip:

I'm kinda sad no one else went for the "condescending half-flame" method I used. Yall are way too nice.

Nah, it just took me a minute to find a good video to reference.

Anonymous:

Skip to about 35 seconds in. See all that stuff jumping around? Imagine that's the inside of your server.

Feel stupid yet?

Even better at 1:25.

Anonymous:

Hehehe... I think my brother have worked there!
This WTF is nothing. My brother have machines that can create giganteous clouds of dirt, my earthquake, everything.

--Tei 

 

The True WTF (tm) is that this site is just a static flash page. What's interactive about it? Well, mouse over the phone and the picture changes along with some text! Click it, and you open a page that immediately tries to print itself!

Boy, this could be done in, oh, 5 minutes with HTML and javascript!

"I'm surprised that this post wasn't anonymized, though. What's up with that?"

Well, he didn't mention the name of the contractor.

Anonymous:

Feel stupid yet?

Yeah, from you and everyone else. ;)

Stupid job is making me dumbr... 

Volmarias:

Anonymous:

Hehehe... I think my brother have worked there!
This WTF is nothing. My brother have machines that can create giganteous clouds of dirt, my earthquake, everything.

--Tei 

 

The True WTF (tm) is that this site is just a static flash page. What's interactive about it? Well, mouse over the phone and the picture changes along with some text! Click it, and you open a page that immediately tries to print itself!

Boy, this could be done in, oh, 5 minutes with HTML and javascript!

 

right, but how enterprisey would that be?

Anonymous:

Not that im saying this actually happened here but its definatley possible, if it required you to "exert force on just the heads" to damage a drive it shouldnt matter what i do with my laptop which is definatley not the case (i went through three drives on one of my laptops).

The time frame wasn't listed, but hard drives used to be a lot more fragile than they are now.  Especially the early Winchester style drives where a platter might be half a meter in diameter and the entire drive was too large for a single person to carry.  Not to mention removable platter drives which were even larger. When a disk crashed, there would always be large and visible grooves dug into the metal.

If I'll ever feel I should start a company, I'll consider the name "Sawhorse Computing".

The real WTF is that the university 'computer scientists' didnt think putting a bunch of servers an an active construction area would be a problem.  Forget the saw horse - but the vibrations for equipment, shocks from lumber being dropped, and dust (those plastic sheets wont stop all of it) could all have damaged the computers.  So while the contractors were pretty dumb (they should never have even touched the computers), putting the computers there in the first place was equally dumb.

 

Anonymous:

Feel stupid yet?

Edit time window expired. Here's what I should have said:

Yeah,
I have only myself to blame for that. Thank you and everyone else for
pointing out how stupid I can be. ;) Let's walk down the avenue of
shame so we can all laugh. I'll be over at the bar, crying to myself.

Let's start with "jigglyness". This hurts: I'm an Engineer. Why couldn't I think of the word "vibration"? Why? WHY?

I
OWN a reciprocating saw! (I've never heard Sabre saw before, which I
assume is American nomenclature, but it sounds a lot better. Total
time: 7 seconds on Google and then wikipedia.) I've used it to (among
other things) cut a tub out of a bathroom, remove a few studs, and
teach an obstinate holly that the previous homeowners have bad arboreal
taste. (Not on the same day.)

I realized as well that he
said, "disk enclosure" and it was 10 years ago. It might have been one
of those monstrous legacy drives purchased in the 1980s for an amount
approaching the GDP of some countries. It certainly could have been
crushed, and if not, then the vibrations from the sabre saw would have
caused the heads to gouge the platters.

Well, there we go. I feel stupid.

Anonymous:

themagni:

I just don't buy it.

When you're cutting wood, you're not using a lot of force. You let the tool do the work. You can easily hold the wood in your hands, although doing such a thing would be silly for several reasons (jigglyness, splinters, etc.)

Take a look at this demo Skip to about 35 seconds in. See all that stuff jumping around? Imagine that's the inside of your server.

Feel stupid yet?

 I think the biggest WTF in that video was at the point where he was sawing and had the cutting edge aimed at his balls.

He was using a saber saw... its like those electric knives you use on your Thanksgiving turkey... only much more powerful. The vibrations can easily cause the disk heads to scratch the platters.

Erm.

The platters are spinning. Let's say that this server got some decent harddrives. So they are probably spinning at 10000 RPM. Disk heads cannot touch the disk, otherwise they will damage it(unless the disk is spinning up, and even then the heads are in the parking area). I hear there is some coating to prevent minor scratches (such as when the disk is spinning up).

The heads are kept above the platters because of their shape and platter rotation, in effect "flying". You just have to apply enough force to counter the air lift. It's not a lot of it. Imagine the head "scratching" the disk at 10000 RPM...

My father used to get hard drives that got damaged because the owner placed a 160 col dot-matrix printer in the same desk as the desktop computer. The wooden desk was somewhat loose, so it did a poor job at absorbing the rocking motions.

Try punching your computer, on the top (if the hard-drive mounted horizontally), do a surface scan and report the results. Or better yet, wait a couple of days before testing, to give time for the particles from the first crash to get in the way of the head, making it crash again, raising more particles, and again...

Hard-drives are sensitive devices, with good reason. 

 

A hand saw probably wouldn't have done it.  But you'll notice the story says saber saw.  As in "electric" ... high vibratation.  It doen't take tons of force, it takes lots of vibration.(and yeah, that's my story.. they embelished a little, but the important details are exactly true; ask people who were working for the CS department when they moved from the Rich bulding to the AECAL/College of Computing building)(neat to see my name in bold :-)  )

Anonymous:

 I think the biggest WTF in that video was at the point where he was sawing and had the cutting edge aimed at his balls.

I see no reason to believe that that cutting edge could get through his jeans.  Didn't look very sharp to me.

Phew, I thought I was going to read that all my data  during my six years at tech was exposed on a webserver somewhere.

Anonymous:

I think the biggest WTF in that video was at the point where he was sawing and had the cutting edge aimed at his balls.

I was thinking, "Oh, this is going to get gory."

The first rule of cutting is "never cut towards yourself."

The second rule is "you will only forget this rule once."
 

themagni:

I just don't buy it.

When you're cutting wood, you're not using a lot of force. You let the tool do the work. You can easily hold the wood in your hands, although doing such a thing would be silly for several reasons (jigglyness, splinters, etc.) Even if you do provide a lot of force for some reason (let's say they climbed on the wood) you'd still be hard-pressed to damage the server. The cases are made out of sheet metal, and they're boxes. People used to put CRT monitors on them ALL THE TIME.

Are the disks outside of their protective dust case? Are they not in the metal case? I have never seen a disk drive just sitting out on a bench waiting for wood to be placed upon it.

In order to force the heads to scratch the platters, then you're going to have to exert force on just the heads. You can't selectively do that when the disks are in their shells, in the server case, in the rack. The only possibility would be if the university's critical server was taped to the top of the case, with its protective dust cap removed in the middle of a construction zone.

What kind of setup is that? I'm going to say it's a "fictional" setup.
 

 As an ex-carpenter turned DBA, I can tell you that the gentleness in cutting wood you have detailed above, isn't the norm. All it would take is to carelessly slap a wet 2x6 or 2x8 down on to the case and pound that thin sheet metal cover momentarily onto the drive. Not all contruction workers are craftsmen and many are high or just don't give a shit.

 Additionally, I'm thinking that this server could be one of the thin rack types where there's barely enough room for the drive to slide in. The depression in the sheet metal wouldn't even necessarily be permanent or visible after the damage was done.

themagni:

Well, there we go. I feel stupid.

No matter. Just being able to admit that makes you smarter than a lot of people who turn up in discussion fora. We all say (type) silly things sometimes.

Anonymous:

The time frame wasn't listed, but hard drives used to be a lot more fragile than they are now.  Especially the early Winchester style drives where a platter might be half a meter in diameter and the entire drive was too large for a single person to carry.  Not to mention removable platter drives which were even larger. When a disk crashed, there would always be large and visible grooves dug into the metal.

Remember the 'park' command? I can't remember if you had to issue the command every time before turning off the computer, or only if you were moving it. But it moved the head over away from the platter, or at least the sensitive bits.

 And I agree with whoever made the point about trusting a server to such an environment. Could they have not moved it somewhere else?

By the way, Carpenters don't use Saber saws to cut a loose piece of wood to size, they use circular saws with a worm drive ( say SkillSaw ). A saber saw is only used to cut wood out of an existing wall or something like that.

You really are all just a bunch of computer nerds, aren't you. Just becuase you've seen a Home Depot comercial it doesn't make you a real man.

 

themagni:

I was thinking, "Oh, this is going to get gory."

The first rule of cutting is "never cut towards yourself."

The second rule is "you will only forget this rule once."
 

The third rule is "If you do forget a second time, aim towards a vital organ."

rmg66:

By the way, Carpenters don't use Saber saws to cut a loose piece of wood to size, they use circular saws with a worm drive ( say SkillSaw ). A saber saw is only used to cut wood out of an existing wall or something like that.

You really are all just a bunch of computer nerds, aren't you. Just becuase you've seen a Home Depot comercial it doesn't make you a reak man.

<obligatory spelling police mode> 

I don't know, after a project day, I tend to reek ... And I can certainly wreak some havoc ... :)

(p.s. I know the difference between a saber saw and a circular saw ... I have a couple of each). 

</obligatory spelling police mode> 

Well, it's far too late for me to point out that when vibrating the case the hard disk heads will stay mostly stationary, and therefore the heads will move relative to the disk platters.  It's maybe more clear to say that the platters crash into the heads, since the heads are minding their own business while the case and platters move towards them.

The effect is the same as if you had magically reached into the case and vibrated the heads directly.  Hard disk specifications include how much force and with what acceleration profile you can vibrate your hard disk.  If you exceed these specifications you typically cease to qualify for warranty replacement, at least on paper.

Another thing to remember is that large boards resonate.  If the board is vibrating freely, and starts to resonate, then comes into contact with something, it is going to put the kinetic energy of several strokes of the saw into the collision.  It's possible to bend steel beams by a small vibration combined with resonance, even steel beams that normally withstand tons of force.

There is a tiny air gap between the heads and the platters, which holds the heads at exactly the right height for read/write operations.  If that gap disappears, the disk heads act like a cutting bit in a lathe on the disk platters, among other things destroying the aerodynamics of both surfaces.  After that, the disk is going to make noises like a tin can caught in a lawnmower, with proportional levels of data destruction.

The insides of hard drives are covered with a very sticky adhesive.  It traps any dust or particles that do appear in the disk enclosure, and can get surprisingly dirty after a few years of use (it bonds like ultra high strength fly paper or those sticky paper mouse traps).  This adhesive tends to make "minor" collisions between the platter surface and disk heads stay minor, as any loose particles that emerge are sent by centrrfugal forces to the side of the drive enclosure where they get stuck forever.  The data under the impact zone is totally destroyed, of course, but if you manage to avoid damaging the heads too much the drive will remain usable after some sector remappings.

rmg66:

By the way, Carpenters don't use Saber saws to cut a loose piece of wood to size, they use circular saws with a worm drive ( say SkillSaw ).

 

Not if you're lazy and careless. You know, the kind of guy who would use some random piece of running equipment to brace the wood... :)

Anonymous:

Hehehe... I think my brother have worked there!
This WTF is nothing. My brother have machines that can create giganteous clouds of dirt, my earthquake, everything.

--Tei 

 

 WTF?! Does your brother not believe in hyperlinks... or even content?!
 

Anonymous:

rmg66:

By the way, Carpenters don't use Saber saws to cut a loose piece of wood to size, they use circular saws with a worm drive ( say SkillSaw ).

 

Not if you're lazy and careless. You know, the kind of guy who would use some random piece of running equipment to brace the wood... :)

This is not careless, this is truly enterprisey. The guy installed the plank on the file server (maybe he had heard something about a certain command called 'mount') and then used cutting edge technology.

Anonymous:

I wouldn't expect a construction worker (who presumably spends more time hammering and sawing than typing) to understand the damage they are doing to computers/drives/whatever, but I would imaging someone from the university should have been there to make sure this type of thing (as opposed to unplugging the servers to plug in the radio) didn't happen.

I think most construction workers can figure out that an appliance with all kinds of cables coming in and out of it, blinky lights and whirring fans probably shouldn't be pounded on--especially in a mystical university science type room.