On 12/06/2011 12:02 PM, Peter Jakobi wrote:
> 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,

Not see a difference between noop and cfq.  :'(

Thank you for the help,
-T


# ls -al rustymapes.ogg
-rwxrw-rw-. 1 todd users 5780060 Sep 30 11:37 rustymapes.ogg

# cat /sys/block/sda/queue/scheduler
noop anticipatory deadline [cfq]

# date; cp rustymapes.ogg /mnt/R/cfq; date
Tue Dec  6 12:19:38 PST 2011
Tue Dec  6 12:20:09 PST 2011


# echo "noop" > /sys/block/sda/queue/scheduler
# cat /sys/block/sda/queue/scheduler
[noop] anticipatory deadline cfq

# date; cp rustymapes.ogg /mnt/R/noop; date
Tue Dec  6 12:20:39 PST 2011
Tue Dec  6 12:21:10 PST 2011