Hello SuSE folkz, I'm sorry for these strange questions After reading "Web Performance Tuning" 2nd Edit. 2002 by Patrick Killelea Pub.O'Reily. ISBN 0-598-00172-x I have the following assumptions: Linux kernel uses buffered IO file access when it's reading and writing to the physical partition/device with its native FS. Linux kernel uses unbuffered IO file access if a program (e.g. DB engine) reads and writes to the raw partition/device. I assume it's because DB engine handles its data transaction on raw device/partition without going through the kernel IO calls. Does all above apply to the case if drives support DMA? Why it's nessesary to bind raw devices to block devices ( bind /dev/raw/raw1 to /dev/hdb1 ) if a database engine reads and writes to the raw partition without such binding? Will this binding improve performance of the DB engine or this needs to be done only in order to read from Linux what has been written on a raw device? Thank you in advance for any answers or sources of further information. Alex