Shh! Disk drive at work.

by Robin Harris on Friday, 2 January, 2009

Funny and provocative video (thanks David!) from Sun demonstrating 2 things:

  • 15k drives are vibration sensitive – in this case to a shout a couple of inches away.
  • That Sun’s Fishworks analysis suite enables realtime analysis of storage behavior.

Bad, bad, bad vibrations. . . .
Vibration issues are old news to the mechanical engineers who design enclosures. The Tsunami Harddisk Detector uses that fact for earthquake detection.

A commenter on Brendan Gregg’s Fishworks engineering blog claims that replacing fans with bad bearings improved array throughput. That can’t look good to civilians.

The StorageMojo take
With any luck at all we should see a spate of competing videos proclaiming that Brand X enclosures pass the “shout test.” Of course, they’ll probably have to use Fishworks for the demos, which is all to Sun’s good.

I left Sun a decade ago. This reminds me that many of Sun’s best promo ideas come from the techies, not the marketers.

Fishworks is the kind of great technology that has always been at the root of Sun’s appeal. Translating that appeal into sales is Sun’s marketing challenge.

Courteous comments welcome, of course. Fishworks includes Bryan Cantrill’s brilliant Dtrace which I’ve been a fan of for years. Update: The too-often-right-for-his-own-good Wes says the drives aren’t 15k drives. I couldn’t find an RPM citation so I struck the 15k out above. A citation would be appreciated, eagle-eyed readers. End update.

{ 11 comments… read them below or add one }

Louis Gray (BlueArc) January 2, 2009 at 11:08 am

This serves as a good reminder to yell at your vendor’s sales people, and not at the equipment itself. Nice video and good find, Robin.

Devang Panchigar January 2, 2009 at 7:25 pm

Good stuff Robin…..I would surely be interested to see what EMC’s Seismic chamber causes these disk arrays to do…..

Wes Felter January 3, 2009 at 1:02 am

They’re 7.2k drives, and you can’t use Fishworks with non-Sun enclosures.

Wes Felter January 4, 2009 at 1:42 pm

What is this, Wikipedia? You don’t trust me, Robin? :-) All right, here are the specs: http://www.sun.com/storage/disk_systems/unified_storage/7410/specs.xml

Steve Jones January 5, 2009 at 2:09 am

I suspect that it is the rapidly changing air pressure of yelling into the drives this effect. That’s vibration of a sort of course, but air vibration, not mechanically transmitted. I assume the reason this doesn’t happen so much with the very high background level noise of that room is that his yelling has a much higher low-frequency component. If you look at a Hi-Fi loudspeaker, then you’ll see the bass units move much further than the high frequency units.

Of course what this does prove is just how finely balanced disk drives are in a mechanical sense. That’s the wonder, and also the weakness of them. I’m assuming that what happened here is that no data corruption occured and that the drives stop writing when they sense the head moving too far off the data track and what we are actually seeing is a delay put in by the firmware to allow the vibration to dampen down. If this sort of event caused data corruption then that would be far more serious than a glitch in I/O.

Pete Steege January 5, 2009 at 10:24 am

Now let’s see who can find the sound or music that increases drive performance…
What a hoot. Thanks Robin!

Steve Jones January 5, 2009 at 1:11 pm

I forgot to say that this is not just of academic interest if you are buying a camcorder for videoing bands. My Sony hard-drive camcorder gets “buffer overflow” error messages and restarts if I’m too close to a loud rock band, although it’s fine with acoustic acts. If you want to record load sounds with a camcorder then the safest option is probably SSD or tape. DVD recorder camcorders might be OK but avoid hard drive ones.

dipe January 7, 2009 at 2:04 am

Robin,

I love reading storagemojo.com and got some incredible insights over the years but now I am a little grumpy. Sun’s Amber Road with the fishworks framework was long expected and many people were extremely curious about this potential netapp replacement. I watched the videos when it was released in december and must say that I have not seen anything as exciting for a long time. So I was curious what you had to say about it and checked every few days but surprisingly I did not see anything on storagemojo. Now you are suggesting that they have 15K drives which shows that you have read nada about this product. Their tiered storage concept involves a ZFS modification to allow tiering from 128GB DRAM to up to 600 GB flash to 7200 RPM disks. Apparently this product does not need any faster drives, Sun even considers ditching the 7200 disks in favor of 4200 RPM disks to save power and does not expect a huge performance hit.
I would still be interested to read your opinion on the Sun Storage 7000 series.

Alex January 13, 2009 at 12:56 am

I totally agree with Dipe. We had a Sun Storage 7210 unit for evaluation and it was incredible! The hybrid storage pools enabled by ZFS delivered great performance and Analytics is addictive :)

Jonathan Anderson January 20, 2009 at 9:17 am

We have a composite substrate material, for HDD media, which exhibits a very highly damped characteristic that would eliminate this troubling phenomena, and is similar in costs to glass substrate materials. Unfortuantely, we have not been successful to find a company to evaluate this material for the future use in high performance HDD’s. Any interested prospects for an evaluation?

Ludovic Leforestier May 21, 2010 at 4:20 am

Glad to like Dtrace and this video :-)

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