[Dirvish] USB drives causing server lockups.(somewhat ontopic)

Keith Lofstrom keithl at kl-ic.com
Thu Aug 21 06:02:30 UTC 2008

On Wed, Aug 20, 2008 at 11:51:54PM -0500, Richard wrote:
> ... External USB drives with 2.4 kernel ...

Known problem, see:   http://wiki.dirvish.org/index.cgi?USB2Drives

This is a problem between some Linux USB2 mass storage drivers and
some nonstandard implementations of USB2 hard drive controllers. 
It is not a dirvish or rsync problem - it is repeatable by writing
large amounts of data to the drive.  It gets better with 2.6, but
I still see problems.

Suggestion:  consider trying different USB2 hardware, if it is
cheap; you will need to know the chipset.  Avoid Cypress.  I 
have some extra USB2 drives that I'm not using anymore.

Better Suggestion: use external SATA instead.  The SATA drivers
are quite robust in 2.6, and I am told they were adequate in the
later 2.4 kernels, too.  If you use PATA aka IDE hard drives,
like me, they can be adapted with SATA to PATA adapters, see: 


These adapters permit hotplugging on the IDE side, with the
right hdparm stuff thrown at them.  I have noticed a need for
some time delay (wait a minute or two) when hotswapping with
a 2.6.18 kernel;  I'm guessing they were still working out
bugs with device state signalling in HAL, the hardware
abstraction layer.  This is not a problem with earlier and
later 2.6 kernels, and I don't think 2.4.x uses HAL.

All the adapters with JMICRON converter chips I have tried so
far have worked, on 4 or 5 different adapter boards.  These
typically cost $20-$40.  A PCI-slot 4 port SATA controller is
also around $40.  Since SATA is becoming cheaper than IDE, 
and is faster than IDE and USB2, this is the best long term
way to go.

If you learn something new, add it to the wiki.  Good luck!


Keith Lofstrom          keithl at keithl.com         Voice (503)-520-1993
KLIC --- Keith Lofstrom Integrated Circuits --- "Your Ideas in Silicon"
Design Contracting in Bipolar and CMOS - Analog, Digital, and Scan ICs

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