On Mon, 25 Jun 2007, Justin Piszcz wrote:

Neil has a patch for the bad speed.

What does the patch do?

In the mean time, do this (or better to set it to 30, for instance):

# Set minimum and maximum raid rebuild speed to 60MB/s.
echo "Setting minimum and maximum resync speed to 60 MiB/s..."
echo 60000 > /sys/block/md0/md/sync_speed_min
echo 60000 > /sys/block/md0/md/sync_speed_max

sync_speed_max defaults to 200000 on this box already.
I tried a binary search of values between the default (1000) 
and 60000 which resulted in some pretty weird behavior:

at values below 26000 the rate (also confirmed via dstat output) stayed 
low.  2-3MB/s.  At 26000 and up, the value jumped more or less instantly 
to 70-74MB/s. What makes 26000 special? If I set the value to 20000 why 
do I still get 2-3MB/s actual?

--
Jon Nelson [off-list ref]