Direct/Buffered I/O

From: <mccmx_at_hotmail.com>
Date: 18 Jul 2005 00:42:09 -0700
Message-ID: <1121672529.662946.160760@g47g2000cwa.googlegroups.com>

Oracle 9.2.0.4 EE on HP-UX 11i

I have a question relating to HP-UX file I/O:

As far as I am aware HP-UX is capable of Direct I/O (i.e. bypassing the

Unix buffer cache) when using VXFS and the following mount parameter:

convosync=direct

This parameter is not used in the mount options in /etc/fstab so I am assuming that I am double buffering on I/O operations.

However is there any way of 'proving' that a particular operation is going via the OS cache or not. If I tusc/truss the process I will just

see pread() calls which may or may not turn into an OS cache hit.

Matt Received on Mon Jul 18 2005 - 02:42:09 CDT