On 26/07/2010 11:24, Keld Simonsen wrote:
[...]

Did you try:

# Set read-ahead.
echo "Setting read-ahead to 64 MiB for /dev/md3"
blockdev --setra 65536 /dev/md3

That'll set read-ahead to 32MiB, because blockdev works in sectors.

Cheers,

John.