Slashdot Mirror
Protecting Hard Drives From Jackhammers
Faramir writes: "I need some help with a jackhammering problem. You see, construction is going on, oh, about 5-10 feet behind the wall of the lab I work in. Essentially right next to my head. And next to this wall I have a number of PCs and a file server with a bunch of nice SCSI drives. And I have no idea how long it is safe to leave them running." (Read more below.)
"I can look at the vibration tolerance specs for the hard drives (my main concern), but translating this into jack hammer vibrations is beyond my ken. Also beyond the manufacturer's tech support, as I suspected. Any clues? Suggestions? Thanks!"
Perhaps the same principles apply to protecting hard drives from loud music, but since heavy-duty laptops aren't much of a solution for holding a rack of SCSI drives, many of the options mentioned there might not apply.
Back when I was interested in holography, there was an "el cheapo" technique used to damp out vibrations. (Hey, if your building a basement holography lab, you can't afford the "good" [read: expensive] stuff.)
Anyway, one of the tricks, aside from the usual foam and stuff, was to get an innertube (from a bicycle or car), fill it only part way with air, and sandwich it between two sheets of plywood (or some similar material).
That will take out a lot of vibration.
Also, put a small mirror on your equipment. Bounce a laser (solid state laser pointers are a couple of bucks down at the drugstore/recordstore these days) off the mirror and across the room. It provides a good indicator of the vibration.
Maybe you could temporarily arrange to work and have the equipment on during hours when construction isn't happening.
For a vibration and impact shock wave resistant material to go under the equipment, look for some stuff called Enkasonic. When I last looked into it, it was made by BASF in a facility of theirs somewhere in the western part of North Carolina. Look it up on Google. Good luck.
I see even classic Slashdot is now pretty much unusable on dial up anymore.
move them.
Seriously. If the information on those drives are at all important, then you should either move them to the other side of the lab, or out of that room (cooling maybe a factor if they leave the room).
The basic sleazeware produced in a drunken fury by a bunch of UCBerkeley grad students was still the core of BIND. --PV
One nice thing about the closed-cell foam is that it can be cut, so one pad can handle several pieces of hardware.
One problem with them is that they are effective insulators--this is bad for anything that vents out the bottom.
Finally, and just for the sake of argument, I'd (gently) topple any towers--lay everything horizontally.
--The basis of all love is respect
Check out EAR
They make all kinds of vibration control stuff - good for low amplitude stuff like you are seeing
Remember one important thing, a poorly designed vibration damper can make things MUCH worse! If the resonant frequency of the damper happens to fall near the fundamental frequency of the vibration, you will get amplification, NOT reduction! Worse yet, if those frequencies happen to be near the critical (aka resonant) frequencies of your hard drives. BTW the greater the damping over the longer the bandwidth, the larger the amplification
These guys offer a bunch of information on vibration and shock. I took Wayne's course at his old company back when I was doing vibration testing for a living - They were the only guys doing vibration testing courses in the early 80s
-- 73 de KG2V For the Children - RKBA! "You are what you do when it counts" - the Masso
You mean something like this?
Those shakers are nothing but BIG stiff air or water cooled speakers - They typically start at around 10 KILOWATS and go up from there. One of the systems I ran was 23 KVA, and the other was a tad over 100 KVA. I had the biggest amps on the block
-- 73 de KG2V For the Children - RKBA! "You are what you do when it counts" - the Masso
Several people have already mentioned part of this approach, but not combined it.
1) Suspend a steady platform with bungee cords, ropes, whatever. It's far more important for it to be flexible than stretchy. You probably want to attach a few cords on the bottom to stop swinging - these should be stretchy.
2) Add extra mass to this platform - something like a layer of bricks. This will put the suspension cords under more tension (which allows them to transmit more vibrational energy), but the extra mass of the system should decrease the motion seen.
3) On top of this platform, put the partly inflated inner tube mentioned elsewhere. This platform holds the computers.
This is more complex than a single suspension system, but a single system will still transmit some key harmonic frequencies. But it's unlikely that two independent systems will share harmonics so there should be very little energy transmitted into the disks.
For every complex problem there is an answer that is clear, simple, and wrong. -- H L Mencken
Sandbags are great for eliminating vabrations. Most of the other posters on this thread have mentioned using something massive (like steel or granite) or something soft (like rubber or foam) to isolate your equipment from the vibrations. Sandbags have both qualities and are cheap as dirt too [ok, bad pun, couldn't help it]. Only thing to be careful of is making sure that your floor will support several hundred pounds of sand.
I don't want free as in beer. I just want free beer.
Unless, of course, your real question is this previous Ask Slashdot.
sulli
RTFJ.
Vibration is one of the worst things for hard disc drives, as the moments repeat themselves. Most G specs for drives are for a one-time shock. Disc drive suceptibility also depends greatly upon the orientation of the drive to the shock as well. Drives ae USUALLY (may vary by drive construction...) much less sensitive when the shock in in the same plane as the platters.
If this is a rack-mounted installation, try industrial equipment isolator pads. Little round things that go between the bottom of the rack and the floor. For desktop or similar, see if you can find an old wavepad from underneath a typerwriter (don't worry, son, look in a museum...) or a half-inch pad of Sorbothane (Costly, ouch....)
*whup* "Get along, little electrons. Heeyah!"
Trolls throughout history:
Trolls throughout history:
Jonathan Swift
It depends, of course, on how long it has been since your last backup and weather there is money in your budget for replacement drives. ;)
I mean, if there's a lot of vibration transmitted through the building structure, you are going to have a lot more to wory about than just the drives having a headcrash.
Gentoo Sucks
While you're dealing with the vibrations, be sure to watch out for the dust -- where you've got one, there's a good chance you'll be dealing with the other.
I wouldn't try to protect the systems in any way -- just keep an eye on their outside cases and be prepared to clean a little more often. I neglected this in an at-home machine several years back while some wallboard was being fixed, and what I found inside after the work was done was a bit alarming. If I'd just dusted the case often with a clean cloth, I could have kept a lot of that dust away from the components.
I hope the construction goes away soon. It's not much fun.
Annie
DUCT TAPE: The Election Supervisors' Secret Weapon
Well, you could pick up a shock-absorbing rack. They're expensive as hell, but if this jackhammering is going to be going on for a while (hope you have earplugs!) then it may be worth your while.
Here's one url:
http://www.martindaleassoc.com/its/4xpcmenc.htm
You can probably find more thru google or av. Meantime, get those puppies as far away from the vibs as possible. If you can power the drives off , all the better. It may not totally save them, but hard drives can take a lot more shock when stopped than when running.
OK, here's how it works: a small chip analyzes incoming vibrations and sends out a sound signal which is a negative mirror image of the original sound, just at the right phase.
Here's where you can get it: NCTI
Unfortunataly they only sell small consumer electronic devices, so I guess you'd have to count
the number of disks you have, buy 1 antinoise headset for every disk, put the headsets on the disks, and off you go!!!
Couldn't be more simple than that (and from only $39, its a steal!!!)