Some settings for linux on compact flash.
http://www.linuxhowtos.org/System/iosched.htm
http://www.staldal.nu/tech/2009/11/15/linux-with-mounted-read-only-2-0/
From reading on the internet it seems that it is better to use noop scheduler for os on compact flash or non-hard disk storage like ssd.
Keywords: compact flash linux usb