#10045 HIGH 1.5-sof: XO-1.5 Record audio/video are out of sync with each other

John Gilmore gnu at toad.com
Tue May 11 17:23:00 EDT 2010


There's a classic Unix problem with distribution of disk access times
that relates to how older Unixes did "sync" -- every 30 seconds there was
an instant traffic jam at the interface to the drives.  This has been
studied to death; here are some assorted papers:

  http://www.cis.upenn.edu/~jms/usenix.pdf
	Has graphs from old DEC hardware that look similar to XO-1.5.

  http://www.usenix.org/events/osdi06/tech/nightingale/nightingale.pdf
	Good references section.

  http://www.eecs.umich.edu/Rio/papers/chen96_2.pdf
	Studies ext3 performance in depth.

Most such studies looked at read() times because the usual workload has
far more reads than writes.  Odd delays in write() times are interesting.

	John



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