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Why Not To Shout At Your Disk Array

timothy posted more than 5 years ago | from the that's-what-your-subordinates-are-for dept.

Data Storage 125

Brendan Gregg of Sun's Fishworks lab has an interesting video demo up at YouTube demonstrating just how bad vibes, if expressed with sufficient volume in front of a rack full of disks, can cause a spike in disk latency. White noise, evidently, doesn't do them much harm. (Maybe they just feel awkward to get yelled at on camera.)

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That explains a lot (-1, Troll)

Anonymous Coward | more than 5 years ago | (#26297917)

I always thought niggers' computers were slow because they didn't know how to use 'em but now I guess it has a lot more to do with the fact that niggers are loudly hootin' and hollerin' all the damn time.

I would never hire an overgrown chimpanzee to work with me at my Pixar rendering farm, that's for damn sure. Good CGI depends on Maya, [autodesk.com] not on mayates [urbandictionary.com] .

Youtube comments (5, Funny)

slugtastic (1437569) | more than 5 years ago | (#26297927)

...always made me laugh.

he's like the crocodile hunter of loud server rooms

Re:Youtube comments (2, Funny)

owlstead (636356) | more than 5 years ago | (#26298007)

...always made me laugh.

Yeah, they get you less tense.

Re:Youtube comments (0)

Anonymous Coward | more than 5 years ago | (#26298779)

no me lo creo

Re:Youtube comments (1)

HAKdragon (193605) | more than 5 years ago | (#26299251)

por que no?

Re:Youtube comments (1)

ta bu shi da yu (687699) | more than 5 years ago | (#26298801)

The video was pretty freaking hilarious as well!

Re:Youtube comments (0)

Anonymous Coward | more than 5 years ago | (#26298903)

Oh no, he isn't a giant fish!

Obligatory.... (-1, Offtopic)

ChrisGilliard (913445) | more than 5 years ago | (#26297933)

Imagine a Beowulf cluster of those things!

Maybe this is why Windows gets slower all the time (5, Funny)

Anonymous Coward | more than 5 years ago | (#26297937)

People yelling too much at their computers

Re:Maybe this is why Windows gets slower all the t (5, Funny)

Gandalf_Greyhame (44144) | more than 5 years ago | (#26298355)

hmm, bit of a chicken and the egg scenario there, isn't it?

is it slow because you yell at it, or do you yell at it because it is slow?

Either way, in the end it only degenerates into a downward spiral, where the computer gets slower and slower, while you get more and more pissed off at it and yell louder...

Re:Maybe this is why Windows gets slower all the t (0)

Anonymous Coward | more than 5 years ago | (#26298399)

Or maybe it's even more complicated than that. Perhaps the user first shouts at his pc because he expects his machine to be crummy on windows and the first slightest mistake is magnified in a placebo effect.

That then begs the question, which came first: window's horrible reputation due to people yelling at their machines or people yelling at their machines due to window's horrible reputation?

Re:Maybe this is why Windows gets slower all the t (1)

YpsiGeorge (1443435) | more than 5 years ago | (#26300461)

Perhaps the converse is true? Are Macs more reliable because their owners are happy (and never yell)?

Re:Maybe this is why Windows gets slower all the t (0)

Anonymous Coward | more than 5 years ago | (#26298881)

So, it's like a positive feedback loop ?

Why isn't this under idle? (4, Informative)

rolfwind (528248) | more than 5 years ago | (#26297943)

It's been known for a long time vibrations are not good for discs (see notebooks). Even by early 90s music CDs had skip protection. If a disc skips, latency will of course momentarily increase. And with tolerances down even further, it's probably worse than back then.

In 10-15 years it won't matter anyway, almost everything will have SSD by then.

Re:Why isn't this under idle? (-1, Redundant)

ChrisGilliard (913445) | more than 5 years ago | (#26297981)

That is true, SSD would not have this problem.

Re:Why isn't this under idle? (1)

Architect_sasyr (938685) | more than 5 years ago | (#26298037)

Unless the increase in noise levels causes a fluctuation in the power going to the write capability of the SSD thus causing it to "write harder", thereby burning out the sectors much faster. Of course this won't increase latency noticeably as the increased power will write just as fast, though it may cause requirements for larger capacitors so that the drop won't cause further delays farther down the line. Hmmm.



Dear $DEITY don't start pulling that apart, I'm joking.

Re:Why isn't this under idle? (1, Insightful)

Anonymous Coward | more than 5 years ago | (#26298073)

On a bright side, you can read all the crap without having to tolerate that god aweful stylesheet!

Re:Why isn't this under idle? (4, Interesting)

Chris Snook (872473) | more than 5 years ago | (#26298263)

Prior to the advent of skip protection in portable CD players, you could make them skip for several seconds just by shouting at them briefly, because it took much longer to recover from the vibration than the duration of the shock itself.

Re:Why isn't this under idle? (1)

rolfwind (528248) | more than 5 years ago | (#26298385)

Yep. Even on my modern CD sound system with skip protection (cache), if I crank the volume up loud enough, the speakers will eventually vibrate the mechanism for so long as to cause the player to shudder and skip.

Re:Why isn't this under idle? (1)

SerpentMage (13390) | more than 5 years ago | (#26298499)

Are you sure about this?

Let's say that I have my phone in my pocket, will that not affect?

Yes I agree that plain vanilla yelling will probably have no effect whatsoever. BUT what about radio waves?

Not to say it will stop me from buying SSD, just wondering out loud.

Re:Why isn't this under idle? (5, Funny)

trolltalk.com (1108067) | more than 5 years ago | (#26298793)

It's been known for a long time vibrations are not good for discs (see notebooks). Even by early 90s music CDs had skip protection. If a disc skips, latency will of course momentarily increase. And with tolerances down even further, it's probably worse than back then.

There's BAD vibrations, and then there's GOOD Vibrations. [youtube.com]

A good reason for hard drives and blu-ray to die (0)

Anonymous Coward | more than 5 years ago | (#26299133)

The only saving grace for optical media and hard drives will be their cost.

Optical media is damn cheap on a $/unit basis. Portable flash drives are never going to be under a dollar each. There's no profit to be made.

Re:Why isn't this under idle? (3, Interesting)

RobinH (124750) | more than 5 years ago | (#26299743)

"Skip protection" on a hard drive is pointless. This is a fundamentally different scenario. With a CD, you can read the data *much* faster than you really need to read it, because you only need the data fast enough to convert it into sound. Plus you almost always know which piece of data needs to be read next, because the song is linear.

On the contrary, with a hard drive, read speed is (usually) the bottleneck, so you want the data sent to the processor as soon as you can pull it off the disk. Also, hard drives are much more random access, so you can't guess the location of the next read and read it before the CPU requests it. The only thing you can do is cache frequently accessed data in memory, which the operating system already does.

Interesting... (4, Insightful)

TFer_Atvar (857303) | more than 5 years ago | (#26297949)

I wonder if the latency would vary by the pitch and tone of the person yelling. If that's the case, I'd wonder if that could be extrapolated into reconstructing whatever was being said. Granted, if you're yelling that loud, the person in the next county is more likely to hear you first.

Re:Interesting... (5, Funny)

sakdoctor (1087155) | more than 5 years ago | (#26298043)

I would say yes. When I was a teen my mother walked into my room and started moaning about the mess.
Right then, windows blue screened and later I found the hard drive was completely dead. (Think it was a 15GB Maxtor or thereabouts) That cost me some pocket money to replace at the time.

If you have women living in the house, factor this into your backup procedure.

Re:Interesting... (0)

Anonymous Coward | more than 5 years ago | (#26298639)

You must still be in your Mum's basement. When I was a teen I had a 80MB Maxtor, and I left the basement 6 years ago! :-)

Re:Interesting... (1)

whohou (1434521) | more than 5 years ago | (#26299409)

You must still be in your Mum's basement. When I was a teen I had a 80MB Maxtor, and I left the basement 6 years ago! :-)

..to upgrade your 80mb (1000x80) drive? - Moore had you at firm ballgrip for quite some time, then.

Re:Interesting... (3, Funny)

apoupc (569200) | more than 5 years ago | (#26300075)

"I would say yes. When I was a teen my mother walked into my room and started moaning..." I thought this was going to go somewhere else...

Re:Interesting... (0)

Anonymous Coward | more than 5 years ago | (#26300761)

This is slashdot, no one here has a woman living in their house.

Re:Interesting... (5, Funny)

Thanshin (1188877) | more than 5 years ago | (#26298057)

You made me wonder; if the the effect could be detected and "read", a you say, it would be possible to use it as a way of transmitting information to the computer by shouting at it.

I then remembered microphones.

Re:Interesting... (2, Interesting)

MichaelSmith (789609) | more than 5 years ago | (#26298195)

My first computer had a 6502 CPU with BASIC and a machine code monitor in ROM. I found that the cassette interface could be used as a sound card if I configured a tape player to record and play back at the same time. For the output channel any AM radio would do because the CPU only ran a 1Mhz and it was leaky as hell.

Re:Interesting... (1)

yanyan (302849) | more than 5 years ago | (#26298357)

With a very loud set of speakers blaring at your drives, you'd do very well to step out of the room and close the door securely before shouting. Since most machine rooms i've been in were soundproof, i can't help but ask the question,

If you yell at your disk array but are not there to hear it, do you make a sound?

Re:Interesting... (1)

sshir (623215) | more than 5 years ago | (#26300977)

Actually, that's not a bad idea for a covert channel [wikipedia.org] .

Re:Interesting... (1)

TheLink (130905) | more than 5 years ago | (#26299945)

Drive seek times are typically in the order of 1-10ms (depending on whether to adjacent track or full sweep), that means it's 100-1000Hz which at least overlaps human vocal range.

This Discovery (5, Funny)

nitsnipe (1332543) | more than 5 years ago | (#26297969)

It bothers me,
How this guy actually made the discovery.

He must have let off quite a bit of steam towards that rack.

Re:This Discovery (0)

hack slash (1064002) | more than 5 years ago | (#26298081)

Just like have you ever wondered what the first person to discover you could get milk from a cow was doing at the time?

Re:This Discovery (-1, Offtopic)

Rakshasa Taisab (244699) | more than 5 years ago | (#26298137)

Like... Uh... Sucking at his mother's tits?

It's not like it was a great mystery that white liquid that tasted so good...

Re:This Discovery (3, Funny)

Anonymous Coward | more than 5 years ago | (#26300497)

>white liquid that tasted so good

The first few brave adventurers were killed by bulls.

Re:This Discovery (1)

bytesex (112972) | more than 5 years ago | (#26298293)

Not to be a dry pedantic killjoy, but he was probably watching a young calf drinking.

Re:This Discovery (2, Funny)

Killjoy_NL (719667) | more than 5 years ago | (#26298591)

*sniff*
I'm dry and pedantic now

Re:This Discovery (1)

scatter_gather (649698) | more than 5 years ago | (#26301297)

If I had mod points today you would get +1 Funny

Re:This Discovery (1)

In hydraulis (1318473) | more than 5 years ago | (#26299175)

What? In public? Outrageous!

Re:This Discovery (2, Funny)

TheLink (130905) | more than 5 years ago | (#26300033)

And udderly inspired he was.

Q: How did the <insert target cultural/racial/whatever group here> man die whilst drinking milk?
A: The cow sat on him.

Sorry, couldn't resist milking it for what it's worth ;).

Screws in surgery (1)

phorm (591458) | more than 5 years ago | (#26299453)

Years back I broke my ankle and had it screwed together for awhile. The screws are out now, but I've got them saved in a container and - other than the material - they really don't seem much different from those in my shop.

So was there some doctor who moonlighted as a carpenter, and one day looked at a broken, out-of-place bone... then at his workbench wood-projects ... then back at the bone.

Even today, looking at the X-ray of those screws firmly drilled through my bones gives me a bit of a creepy feeling, but I can't really complain about the results as the bones firmly knit themselves back together in the right positions.

Re:This Discovery (2, Funny)

thermian (1267986) | more than 5 years ago | (#26298487)

'The very existence of flame-throwers proves that some time, somewhere, someone said to themselves, You know, I want to set those people over there on fire, but I'm just not close enough to get the job done.'

George Carlin

Re:This Discovery (1)

Penguinisto (415985) | more than 5 years ago | (#26299769)

The guy is a sysadmin. No surprises at all from this quarter as to how he came across such a discovery...

JBODs? (1)

SanityInAnarchy (655584) | more than 5 years ago | (#26297993)

...why?

I'm sure there's a good reason, but... He's using dtrace, right? Thus implying Solaris? Thus implying ZFS?

If you've got ZFS, why would you do JBOD?

Or did I just mis-hear him?

Re:JBODs? (4, Informative)

Anonymous Coward | more than 5 years ago | (#26298053)

If you've got ZFS, why would you do JBOD?

A few reasons.

  • If anything, I'd have figured you're more likely to setup a disk array as a JBOD with ZFS than (say) UFS. After all, you can get ZFS to do RAID0 for you (ZFS can probably also RAID1, but it's better to do that in hardware).
  • Solaris-10 still supports non-ZFS filesystems (VxFS) which I imagine you'd still want to use in some circumstances.
  • Their customers might be running an earlier version of SunOS/Solaris. He might simply be using DTrace to look at a customer bug-report from another prespective.
  • Indeed, even though he's debugging in Solaris, the customers might not even be running Solaris. Sun hardware is really sweet and is supported on both Microsoft Windows and various distributions of Linux.
  • And even if all the above reasons don't apply, using a JBOD is a good way of eliminating variables if you're trying to isolate/trace a potential hardware issue.

Re:JBODs? (0)

Anonymous Coward | more than 5 years ago | (#26298077)

Or did I just mis-hear him?

Obviously he wasn't yelling loud enough

Re:JBODs? (5, Informative)

paulz42 (638751) | more than 5 years ago | (#26298125)

Sure, with ZFS JBODs are the preferred storage. Let ZFS do end-to-end management of the storage, from the file level to the raw disk blocks. That way it can do it's end-to-end error checking and possible correction. If you do RAID1 in hardware ( really just firmware in the storage box) you trust that software to detect all problems and correct them or report them. That software may not do checking to see if both branches of a mirror are correct and pass on bad data upstream. ZFS will detect this because of it's checksums, but it will not be able to correct this. If ZFS is doing the mirroring it will detect it and read the other mirror, if that checksum is ok, it will correct the error and continue.

Re:JBODs? (4, Interesting)

Chris Snook (872473) | more than 5 years ago | (#26298147)

ZFS implements software RAID on top of JBOD. The box full of disks itself need not have any RAID controller, and if you're using RAID-Z, it would probably be a waste of money to spring for one, unless you go for the super-high-end for performance reasons.

Re:JBODs? (2, Insightful)

drsmithy (35869) | more than 5 years ago | (#26298485)

Or did I just mis-hear him?

"JBOD" in this context will be a reference to the style of disk array (eg: vs one with a RAID controller like the Dell MD3000), not the ZFS RAID level.

Is this a feature? (2, Funny)

fragMasterFlash (989911) | more than 5 years ago | (#26298017)

Might the the drives themselves be sensing the induced vibration via an embedded accelerometer and momentarily parking the heads to avoid damage? It seems like the marketing folks shouldn't have too hard of a time putting a positive spin on this behavior.

mod parent up (0)

Anonymous Coward | more than 5 years ago | (#26300521)

sounds right to me.

A rack full of disks (1)

Thanshin (1188877) | more than 5 years ago | (#26298025)

if expressed with sufficient volume in front of a rack full of disks

I wonder about the results of eliminating the superfluous "full of disks" part.

Interestingly enough, it's precisely here, where the omission would both be understood and not bring unwanted connotations.

Great.... (4, Funny)

Whillowhim (1408725) | more than 5 years ago | (#26298027)

Now when Skynet finally goes sentient, it'll sue for emotional abuse. I thought metal death machines were bad, but now Lawyer-bots? We're doomed.

Re:Great.... (1)

Stile 65 (722451) | more than 5 years ago | (#26298419)

You might like Accelerando by Michael Stross.

Sentient corporations and financial instruments and lawyer bots abound. It's a great book.

Re:Great.... (1)

PotatoFarmer (1250696) | more than 5 years ago | (#26299353)

Charles Stross, not Michael.

Re:Sentient Corps and Lawyer Bots (1)

TaoPhoenix (980487) | more than 5 years ago | (#26300641)

In the wake of the Great Crash of 2008 that might take on scary new meaning.

Re:Great.... (1)

cparker15 (779546) | more than 5 years ago | (#26301149)

metal death machines

Just put these in a room with death metal machines. Problem solved.

White noise or not, it's the volume (1)

wdsci (1204512) | more than 5 years ago | (#26298065)

I doubt that white noise vs. voice has anything to do with it. He's yelling *right* in front of the disks - his voice is going to induce a lot more vibration just because he's so much closer than the equipment. Inverse-square decay and all that ;-)

Re:White noise or not, it's the volume (5, Interesting)

Bengie (1121981) | more than 5 years ago | (#26299463)

I'm not an engineer or absolutely sure about how the brain works with white noise, but I had a job that I worked at that when I entered the freezer section, it didn't seem loud at all. Actually, it so much didn't seem loud that the few times I had to enter it, I forgot my ear plugs until I saw someone else using them.

Anyway, even though you couldn't really hear anything 'loud', if you tried to talk to anyway, you could barely hear them.

On to my question. If you have enough high amplitude random noise that is effectively destructive interference, would this make an enviorment where low amplitude sound could not be hear or even mechanically sensed easily?

I know using 'heard' may be incorrect in this context because perceived sound usually has no direct relation with what's mechanically going on with the sound waves.

just a thought... (-1, Offtopic)

Anonymous Coward | more than 5 years ago | (#26298075)

Stud dogs go about the whole sex thing rather differently than primates (or equines). Unlike us, male canines don't have an orgasm that involves a short, intense ejaculation. Instead, once they have become fully erect, they will have a continuous orgasm for from 10 to 45 minutes or longer. The "standard" procedure for dogs, when they are mating, is that the male "ties" with the bitch - which means that, after he has penetrated fully, his penis will develop a knot at its base that is several times wider than the rest of his shaft.

For reference, a 80 pound Golden stud dog might have, let's say, a cock that is 7 or 8 inches long when erect - but his knot will be at least as big around as a tennis ball. This knot swells inside the bitch, and so long as he remains erect the dogs are "tied." No, this isn't painful for her - canine females long ago developed an entire set of muscular supports for this process. Generally, once they are tied, most stud dogs prefer to step off and over, so he and the bitch are tail-to-tail. Theories abound on why this evolved - I have yet to see one that was truly convincing. Anyway, they'll stand like this, with the male having a continuous orgasm during the whole tie - until he starts to shrink and they pop apart. Bitches also have orgasms, and she'll likely have quite a few during the tie, as well - research has shown that her orgasms are essential to increasing the chances of pregnancy, due to muscular contractions.

Anyway. if a guy like me has a stud dog partner, one form of intimacy is for him to tie with us, anally. As young teenagers, many of us learned the hard way about the knot, and the tie - particularly back in pre-interweb days. So we'd suddenly find ourselves locked together, with this tennis-ball width cock inside us. Nowadays, I suspect most young zoos know all about this. However, some folks still have eyes bigger than their stomach, err their you-know-what.

It would not be accurate to say that I have a stream of visitors who show up at my house just for sex with my canine partners. However, it is true that I do not exercise any sort of unilateral control/ownership over the relationships my canine boys might develop with other people - they are adults, and if they desire to get frisky with another two-legger and I judge that the person is respectful and unlikely to do anything mean or stupid, I have no moral ground on which to say "oh, no, you aren't allowed - he can only have sex with me." That just makes no sense, so if there's a time when a friend is visiting and there's a spark between them and one of my partners, I'm ok with that. In truth, I think it's great to have the boys' enjoy other positive relationships and I love to see them happy, whatever the circumstances.

Many years ago, a friend was visiting - a zoo who had been active with his own stud dog for quite a few years. His boy was a breed that is not small, but is also somewhat known by old-school zoos as being, well, on average not so well-endowed relative to their body size. This friend had tied with his partner on a number of occasions - and he often talked about how intense and rewarding the experience was, for both of them. That's great, I said - while thinking that he'd probably not fare so well with a larger breed.

As it turns out, he and one of my canine friends hit it off quite clearly right from the get-go - the chemistry was there and the two of them seemed like they'd known each other for ages. After several visits, I could see that they were sort of getting closer and closer - my friend was worried that I'd feel he was somehow intruding into my relationship with this handsome stud dog - who had been in my own family for close to a decade. Of course not, I told him - if you guys hit it off and things get steamy, I'd hardly throw cold water on it just so I can be all possessive and insecure. HOWEVER, I warned him, that handsome boy with whom you're making goo-goo eyes is much bigger than your own long-time partner.

I tried to be nice about this, but some zoos get their nose out of joint if you suggest their beloved might not be the most-endowed canine (or equine, or whatever) around. He was a bit like that - and right off the bat tried to convince me his boy was "really quite large for his body size," and who was I to argue? I did warn him that the stud dog he was considering, in my family, was somewhat over-endowed for his body size - and he was in the range of 120 pounds of low-bodyfat muscle. Beh, my friend said, no problem - I know what I'm doing. . .

Later that evening, after I'd gone to bed, I woke to the sound of toenails on the hardwood floor. There was also a bit of panting, a giggle here and there - not hard to figure out what was going on. Feeling a sense of impending doom, I made my presence known and sort of lurked in the background, sitting on the sofa and enjoying the huge, nearly-full moon casting shadows on the farm. The two boys were doing some sort of foreplay - it seemed cute to me, but I did (once again) warn my friend that this particular stud dog was also rather aggressive in his breeding - he'd sired many litters of wonderful pups, in his own career, and knew quite well how to get a proper tie with even inexperienced or skittish bitches. Yeah, yeah - my friend was clearly not thinking with the had between his shoulders, but the one between his legs.

In a flash, the big stud dog was mounted on my friend - and this time he wasn't just going through the motions, or playing. In just a few thrusts, he was inside - and with all that muscle, he held himself tight as he began to swell. It doesn't take long - maybe 20 seconds. I'm still watching, from the sofa, somewhere between shocked and bemused. For the first ten seconds or so, my friend is quiet and still as a winter night - not a sound save the deep grunting from my stud dog as he was swelling with each heartbeat.

Then, reality started to intrude (pun intended). My friend started to make this sort of whimpering sound - no words, just a low moan. Too late to turn back, I knew, so I held my tongue. Then, as my stud dog really began to take on his full size (which I knew from years of firsthand enjoyment was just under 10 inches in length with a knot just shy of softball size), my two-legged friend began to realize the error of his ways. This stud dog was, quite likely, at least double the width of his normal canine partner - and 3 or 4 inches longer. And, as reality is dawning on him, each heartbeat is causing the cock inside him to get bigger. . . and bigger. . . and bigger.

By now, he's positively crying - literally crying like a baby. No words, just sort of a quiet blubbering. He's smart enough to know there's no backing out now - and he didn't try anything stupid like pulling loose (which can, indeed, cause massive rectal tearing if done in haste - trust me, not fun). At this point my canine friend casually steps off from the usual "doggie style" position and, with years of practice, adjusts himself into the butt-to-butt position. And to add insult to (literal) injury, my canine friend has now plastered an absolutely massive grin on his face - when we say "shit-eating grin," this is it He's having the time of his life, tied with a new friend he's met, just starting into an orgasm that will go on for nearly 20 minutes. Not only does he not really know that his **** buddy is feeling like someone's put the better part of a baseball bat up his ass. . . I'm quite sure he doesn't care.

Just for good measure, I took a photo of the gigantic smile on the stud dog's face - nothing more than that, just his face and the grin to end all grins. Click.

My two-legged friend is now officially gibbering - it's really a verb, I didn't know that before just then. He's somehow begging for it to "stop, oh please stop" - but every now and then there's an "oh god oh GOD he's amazing" thrown in, before he's back to "oh PLEASE make it stop OOOH stop stop stop." This goes on, as is par for the course, for just shy of 20 minutes, at which point my stud dog friend begins to subside, pops free (with a characteristically loud and gushing dis-connection), and lies down to clean himself up and help his cock back into its sheath.

In contrast, my two-legged friend has simply fallen over, and curled up into a fetal ball. Well, I think to myself, I don't see any blood. . . oh, wait, I do see blood, but not really that much so it's probably ok. I get him a blanket and try to offer kindness without intruding on his pain, and to be honest without s******ing. The words "I told you so" are hovering out there, but need not be spoken at that somewhat awkward time. I do ask: "are you going to be ok, or should we head to hospital?" In between ragged breaths, he responds "no hospital, not going to die" - and indeed my own judgment is that he's far from dying, though he may feel like that would be preferable to the pain he's in.

I get him a blanket, and a pillow and get him comfortable right there on the hardwood floor of the kitchen. And our canine Casanova? Well he's cleaned up, wandered over to give a big, wet, shameless kiss to his worse-for-the-wear sexual partner and he's already asleep on the sofa, snoring - with grin still present on his face. Remorse? Regret? Not a chance!

The next day, I was impressed to see that my guest was up and at the kitchen table, with his well-endowed playmate from the previous night sharing a dish of eggs and toast, when I came downstairs with the rest of the canine crew. Impressed, that is, until I noticed he wasn't in any rush to get up from the table - ever. Turns out, he had indeed suffered some serious internal bruising - in a few days, the discoloration has spread from his lower back (which still makes me laugh, sorry, because I can visualize exactly how far in that cock had gone and, sure enough, that's where the bruise mellows out - a good bit of the way up his back and towards his ribs) down his legs, and clear to his ankles. Both legs. It's spectacular. He's walking like a rehabbed accident victim for several days, and for weeks afterwards he looks as if he'd ridden a horse for too long (again, laughing as I type). It was more than a month before he'd healed up more or less ok, and even then I'd see him wince if he bent down too quickly.

Is it wrong for me to think this is funny? If it is, so be it - it's ****ing funny. The transformation from swaggering "oh I can take that big boy, I know what I'm doing" to hunched-over victim of a mind-expanding lesson in what "big" means when applied to stud dogs - all in the blink of an eye. Yes, it's definitely funny.

Of course, in those early weeks, he promised me he would NEVER do something like that again - NEVER tie with a dog bigger than his own long-term partner. And, he asked me with genuine indignation, how could I keep tying with that dog who had torn him up so badly? Didn't I know the danger I was in? I responded, casually, that I appreciated his concerns but, to put perspective on things he should remember that his dog compared to that stud dog who tore him up so badly, in terms of relative size, the same way that the tearer-upper compared to my Dane partner at the time. His eyes grew wide - comprehension dawned. . . "you don't tie with that monster, do you?" I glanced over at my beloved Dane who, looking up at me, thumped his tail a few times in flagrant collusion with my own thoughts. "Who, me? Tie with that massive dog? Now what kind of crazy fool would do such a thing?"

Re:just a thought... (-1, Offtopic)

Anonymous Coward | more than 5 years ago | (#26298209)

you forgot the ending where it goes

I whistled for a cab and when it came near
The license plate said 'FRESH' and it had dice in the mirror
If anything I can say this cab is rare
But I thought 'Now forget it' - 'Yo homes to Bel Air'

I pulled up to the house about 7 or 8
And I yelled to the cabbie 'Yo homes smell ya later'
I looked at my kingdom
I was finally there
To settle my throne as the Prince of Bel Air

Hard-drives as microphones?` (1)

fluor2 (242824) | more than 5 years ago | (#26298169)

Nice, now I can use this to detect if people were loud in my server-room.

Do they also react to smell?

Re:Hard-drives as microphones?` (1, Interesting)

Anonymous Coward | more than 5 years ago | (#26298477)

Well, you can also use HDs as speakers:

http://www.afrotechmods.com/cheap/hdspeakers/hdspeakers.htm

I heard... (0, Offtopic)

fluch (126140) | more than 5 years ago | (#26298201)

I heard that there is a place where they throw chairs at things...

Like with plants... (1)

dupont54 (857462) | more than 5 years ago | (#26298239)

you need to play classical music to your disks, and they'll perform even better.

Re:Like with plants... (2, Interesting)

freddy_dreddy (1321567) | more than 5 years ago | (#26298347)

The plants publications never seems to die.

Plants don't react to music, they react to the tiny shifts in air just above their stomata. The publication which reported this compared plants with music (read: vibrating air above the stomata) with plants in an enclosure without air vibrating (read:refreshing) above the stomata.
The experiment shows a difference, even if there's air-movement simply because air "sticks" to the surface of plant's leaves in close proximity - behaving like a fluid. Normal air ventilation doesn't refresh this thin layer as optimal as vibrations caused by sound.

It's the Enclosure (2, Interesting)

selectiontimeout (1443281) | more than 5 years ago | (#26298351)

Well, partly at least. It's no secret that disk drives are sensitive to vibration as this video showed an extreme case. Keep in mind, since disk drives are spinning at 7200-15000RPM, they themselves create vibration that can affect adjacent drives. The drive enclosure can help reduce the problem with use of shock absorbers and vibration dampeners. Most drive enclosures nowadays, for cost reasons, are no more than just sheet metal wrapped around power supplies, fans and drives, which contribute to the problem.

Secret Fact : Ultrasonic noise at low volumes ! (5, Interesting)

Anonymous Coward | more than 5 years ago | (#26298367)

Secret Fact : Ultrasonic noise at low volumes is WORSE !

It took weeks to testing to get to the root issue of WD Raptors dropping in head seeks on very high end raid cards in tiny head movement seek benchmarks, but padding each JBOD drive in acoustic foam (shooting range foam), or testing one drive at a time, instead of 4 or 8, (either method works) increased I/O per second by 40% in a rack chassis.

40% more head movements per second if no ultrasonic noise entering drives !!!!!

This is VERY VERY RARE INFO, and only I, the head of Gigabyte in Asia, and two engineers in california know of this discovery.

And because I know no one on Slashdot will mod this up, and no one reads at 0 anymore, I can trust my astounding well researched secret shall remain secret.

Its sadly 100% factual.

Re:Secret Fact : Ultrasonic noise at low volumes ! (1)

Tranzistors (1180307) | more than 5 years ago | (#26298771)

>And because I know no one on Slashdot will mod this up, and no one reads at 0 anymore, I can trust my astounding well researched secret shall remain secret.

For starters, make an account.

Re:Secret Fact : Ultrasonic noise at low volumes ! (1, Insightful)

Anonymous Coward | more than 5 years ago | (#26299323)

Accounts are overrated. What happened to judging the content rather than the person?

Re:Secret Fact : Ultrasonic noise at low volumes ! (0)

Anonymous Coward | more than 5 years ago | (#26300629)

1. Make account
2. Post "secret" info
3. ???
4. Profit!

Re:Secret Fact : Ultrasonic noise at low volumes ! (0)

Anonymous Coward | more than 5 years ago | (#26298901)

How do we know that this is true? That you are the one true head of Gigabyte in Asia?

Somebody PLEASE change the headline to 'Reasons Not to Shout at Your Disk Arrays', before I start yelling at someone. Reading it as it is, is painful. It must have broken some laws in several states.

P.S. I have my stereo speakers next to the PC, and I play the music loud. Are his findings limited to arrays and not just plain ol hard drives in their respective bays?

Re:Secret Fact : Ultrasonic noise at low volumes ! (4, Informative)

thogard (43403) | more than 5 years ago | (#26299023)

You don't know too many greybeards do you? I'm surprised that modern drives are susceptible to ultrasonic under 80 khz but real old drives and drums were known to have problems with low audible frequency harmonics. A simple solution to this problem is stamp a butterfly like pattern in the arm of the head. The same thing works for power lines (which is what the small dumbbell looking things are near the insulators)

If you sing to them will the latency decrease? (1)

netadmin (66549) | more than 5 years ago | (#26298409)

I think that this discovery is just the beginning of a new and harmonious spiritual relationship between man and machine. Just imagine, DC engineers across the world singing beautiful harmonies to their storage arrays!!

Wonderful. ;-)

On colors of sound (1)

Max Romantschuk (132276) | more than 5 years ago | (#26298435)

White noise is just like white light: An even distribution of energy across the spectrum.

It makes perfect sense that white noise is less of a problem than an equal amount of noise at a specific frequency. Given a suitable frequency the material absorbing the energy will vibrate and even resonate. (That particular engineer's yelling, apparently, resonates well with the disks in the array of that video...)

It's the same reason why a bullet-proof west can make the impact of a bullet non-lethal: Spread out distribution of energy.

Re:On colors of sound (2, Funny)

Jaden42 (466735) | more than 5 years ago | (#26298535)

And are those kept near the nuclear wessels?

Sorry, could not resist.

Bad breath ... (1)

Rotaluclac (561178) | more than 5 years ago | (#26298503)

... would increase my latency too.

"anti-vibration" damping?? (1)

karbonKid (902236) | more than 5 years ago | (#26298507)

Having seen this, I wonder what effect the 'anti-vibration' rubber grommets that are used on most modern desktop PC hard drive bays have on disk latency. After all, they stop vibrations being transmitted into the case my allowing the HDD itself to vibrate more and damping the movement as it reaches the case. Of course, having the HDD vibrate of its own accord is much better than having it resonate with another component in the case, so perhaps in some cases, the damping is beneficial to latency aswell.

In fact, I'm surprised that no-one has come up with a case in which all parts have a natural frequency that does not coincide with the speeds of modern hard disks, such that the case will vibrate with HDDs, but not resonate, which is where most sound problems (the reason for damping in the first place) come from.

Warbirds? (2, Interesting)

t0ny747 (849486) | more than 5 years ago | (#26298541)

I was thinking ( more like dreaming ) about buying a HD video camera that uses a hard drive. I wonder how much the noise of flying in a WW2 era Warbird would mess with it. I flew in a B-25 and it someone screwed with my camera's ability to focus.

Also by Brendan Gregg (5, Funny)

Gord (23773) | more than 5 years ago | (#26298571)

Also from Brendan Gregg comes the always useful /usr/bin/maybe [brendangregg.com] . Other funnies from him here [brendangregg.com] .

Percusive Maintenance (0)

Anonymous Coward | more than 5 years ago | (#26298661)

I suppose percussive maintenance is likewise discouraged.

Re:Percusive Maintenance (1)

dgatwood (11270) | more than 5 years ago | (#26300551)

No, that is always recommended. How else are you going to get the bean counters to spring for some new kit?

before making fun of hard disks (3, Funny)

mugurel (1424497) | more than 5 years ago | (#26298707)

go and measure your own performance degradation while your hard disk does something mean to you

the disk whisperer ... (4, Funny)

BigMike (122378) | more than 5 years ago | (#26298739)

I dub this guy the disk whisperer ...

If you think that... (0)

Anonymous Coward | more than 5 years ago | (#26299859)

...yelling at your hard drives makes them upset, then imagine how they'll react if you whip out your wong and start peeing on them.

Re:the disk whisperer ... (0)

Anonymous Coward | more than 5 years ago | (#26299909)

I dub this guy the dick whisperer ...

Re:the disk whisperer ... (1)

spartacus_prime (861925) | more than 5 years ago | (#26299967)

He's not doing much whispering though.

Looking up? (0)

jambox (1015589) | more than 5 years ago | (#26298813)

I'm glad Sun have got enough free time and energy to find out useless nonsense like this.

Re:Looking up? (2, Insightful)

Bengie (1121981) | more than 5 years ago | (#26299573)

because all server admins are busy 24/7?

Server Admins are getting paid to 'watch' the servers. They have plenty of pseudo-free time. It's when stuff is breaking that they're busy. Not to mention a good admin in large server area will have software like that person had to watch drive latency.

Good vibrations (1)

technosattva (761682) | more than 5 years ago | (#26299227)

Now that this has been demonstrated, I'd like to ask for generous funding and unlimited access for doing studies to demonstrate the effects of good vibrations on hardware.

In case anyone hasn't seen it, I think I'm the first to have a data center blessed by a Tibetan Buddhist Lama. http://picasaweb.google.com/nagardner/200709LamaSamtenBlessesTheInternets# [google.com]

I am currently hoping to see research on the long term effects of hanging prayer flags in data centers. My hypothesis is that if they would make for nice photos and surveillance videos, and would have a net improvement on the MTBF of hardware and personnel.

LOUD NOISES (0)

Anonymous Coward | more than 5 years ago | (#26299387)

LOUD NOISES

What about my 300W Sub (1)

Rashkae (59673) | more than 5 years ago | (#26299443)

That thing can shake my whole apartment. Is anyone testing what effect this thing has on my hard drives when listening to music/playing a game?

Re:What about my 300W Sub (0)

Anonymous Coward | more than 5 years ago | (#26300197)

If you feel the need to give your sub(s) enough power to noticibally shake the appartment maybe you should consider shopping for a hearing aid.

Now I'm terrified (1)

tuxicle (996538) | more than 5 years ago | (#26299623)

Seems like I have a lot to worry about, I have a couple of disk arrays inside a 40-ft trailer that tends to rock in the wind...

The racks are shock-mounted, though.

You just scared them... (1)

punkrocher (775394) | more than 5 years ago | (#26299669)

you insensitive clod! Give them a bit to recoup!

Nice Viral Marketing (1)

eudaemon (320983) | more than 5 years ago | (#26299797)

I'm not being cynical in any way when I say I spent the last 1/2 hour checking out Fishworks due to the interesting analytics screen he used during the video. It occurred to me just now that's some (whether intentional or not) pretty effective viral marketing. LOL. The bad news is it appears Sun hasn't released Analytics as part of the base OpenSolaris distribution just yet. Too bad. I could just as easily use it to look at Veritas storage, assuming Veritas played nice with DTRACE. It'll be interesting to see what this looks like when Sun uses this on top of iSCSI served SAN disks instead of NAS. Don't know about you, but I don't park database filesystems on NAS. Perhaps that is outmoded / old-school thinking but that's the way it is.

Disk Drives have a resonant frequency (5, Interesting)

thethibs (882667) | more than 5 years ago | (#26300617)

Disk drives have a resonant frequency

I've seen dramatic demonstrations of this over the years. One that stands out was a test of a Bryant drive sometime around 1970. In those days a 2 GB drive was at the edge of the envelope and Bryant was test-marketing just such a beast. It consisted of eight four-foot platters mounted four to a side on a shaft going through a monster of an electric motor. The heads were mounted on arms whose positioning was controlled by hydraulic cylinders big enough to be used as shocks on a pickup truck. The whole thing would not fit in the back of that pickup truck.

We were testing the thing with a program called the "Leese Bomb". Leese can identify himself or remain anonymous--I won't turn him in. The "Bomb" part was the nature of the test.

Basic tests in those days would involve writing a whole track and then reading it back and comparing what was read to what was written. You'd do this a number of times with different patterns to capture not only faults in the surface, but any sloppiness in the head control. The Leese bomb went one better.

It would write to the outside track, write to the inside track, read the outside track, read the inside track, and then compare. If the comparison failed it would repeat the test, and keep repeating untl it succeeded, counting the failures. If the test succeeded it would index the test both inward and outward so that the tracks tested would move toward the middle, cross, and continue. This test was superior in that it would capture dynamic flaws in the system as the distance the heads moved, and the time to move varied from max to zero.

In the case of the Bryant Drive (and, accidentally, an innocent Ramac drive at Caltech), the test found a resonant frequency. When the heads overshot their mark causing an error, the test stayed on the back and forth pattern, reinforcing the resonant motion with each cycle of the test. The drive started walking across the test floor in three-inch hops, but not for very long. In a few seconds, one of the shafts broke and one of the platters, a 500 pound disk rotating at 2400 rpm broke through the front of the unit and flew across the building until it was stopped, explosively, by one of the steel columns supporting the roof of the building. Miraculously, no one was hurt.

We gave up on Bryant for that application. Not long after that, CDC introduced its 200MB drives, and they passed the Leese Bomb with flying colours. Ten of them didn't take up any more room, or cost more, than the big Bryant, so our client was happy to go with that solution.

In any case the lesson is that, if it has moving parts, resonance is an issue.

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