From: Inaam Rana 
> Which IO Shceduler (elevator) you are using?
 
Elevator?  Sorry, I'm not familiar with the kernel implementation, so I don't what it is.  My Linux distribution is Red Hat Enterprise Linux 4.0 for AMD64/EM64T, and the kernel is 2.6.9-42.ELsmp.  I probably havn't changed any kernel settings, except for IPC settings to run PostgreSQL.