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
