On Tue, Dec 06, 2011 at 08:41:09PM +0100, Florian Philipp wrote:
> Am 06.12.2011 19:15, schrieb Todd And Margo Chester:
> > 
> > Extra info.  If I boot off a Fedora Core 16 Xfce Live CD, I
> > can copy my files to flash drive at full speed.  It is a pain
> > in the neck, but it works.

I  was  a  bit  pissed  b/c  of a similar  issue  this  week  as  well
(non-centos, ubuntu lucid, kernel 3.0). 

checking  mount  options (async, stripping any  remaining  prehistoric
dirsync or other artefacts) and

   cd /sys/block/sda/queue && ( echo noop >  scheduler; 
   test -f rotational && echo 0 > rotational )

made it behave and restored _reliable_ writing.

[   current  cfq  is said to recognize flashes, but it doesn't for me
    (rotational  was still 1), worse: using cfq degrades to less  than
    100KB/s writes for me, 100% reproducible after copying a few GB (AFAIR,
    always  after copying 'more  than physical RAM' GB, so it is  some 
    kind of device-specific buffer reuse bug, maybe also vfat  related 
    or related to  flaky readers. However there's nothing in the logs).
]

Hth,
-- 
cu
Peter
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