Shouting in the Datacenter

Brendan Gregg from Sun's Fishworks team makes an interesting discovery about inducing disk latency. For more details, see Brendan's blog entry: http://blogs.sun.com/brendan/entry/un...

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  Science & Technology

[xamanto]

This proves hard drives are operated by little men.

If you shout at them, they get scared a little and stop working for a moment.

[Milos Kaurin]

FUS RO DAAAAAAAA

[Chris Sherlock]

Hi Brian, have you ever kissed a girl? For real?

[Dylan Coulston]

haha good video!

[James Bos]

If being a sys admin doesn't work out, you have a promising career ahead of you as a hardcore singer!

[Brendan Gregg]

It was Sun Storage Appliance 7000 Analytics. Now called Oracle ZFS Storage Appliance Analytics. In particular, I was showing heat maps of disk I/O latency - which are crucial for examining the full distribution of latency over time. Similar heat maps are now in Joyent Cloud Analytics. In both cases they used DTrace to fetch the data.

[Brendan Gregg]

I explained the story in another video on youtube, titled "The Making of Shouting in the Datacenter" (comments won't let me include the link)

[Brendan Gregg]

no, I've spoken to hard drive manufacturers about it - load noises or vibrations are a well known problem for rotational disks. If you'd like to read more about it, look up "Effects of Data Center Vibration on Compute System Performance" by Julian Turner, USENIX, 2010.

[Shawn Hartsock]

It's amazing to me how much basic science we need to do in our field. Have you tried isolating the noise with different noise makers? For example: a fog-horn from 3 feet versus a speaker.

[windows7rocks1]

It's not that you are shouting at them, it is that your hands hit them when you put them up against the enclosure. That is the main vibration source and it explains why the spike is shorter than the time you shouted for, especially the second attempt.

[Marcio Y]

Hard drives have voice coil actuator for the heads positioning. These actuators position the motor like the baffle of a loudspeaker, so there is the name - voice coil

[TheVideoSupreme]

not on mine, maybe it's because you were listen to jbiebs earlier?