Veritas Storage Foundation for Oracle 5.0 Administrator's Guide, HP-UX 11i v3, Second Edition, December 2008

Enabling Concurrent I/O
Because you do not need to extend name spaces and present the files as devices,
you can enable Concurrent I/O on regular files.
Before enabling Concurrent I/O, review the following:
To use the Concurrent I/O feature, the file system must be a VxFS
file system.
Make sure the mount point on which you plan to mount the file
system exists.
Make sure the DBA can access the mount point.
Prerequisites
When a file system is mounted with the Concurrent I/O option, do
not enable ODM. If you try to enable ODM on a file system mounted
with the Concurrent I/O option, you will get an error message
similar to the following:
ORA-600: internal error code, arguments: [ksfd_odmopn2].
If Quick I/O is available and a file system is mounted with the
Concurrent I/O option, do not enable Quick I/O. (Quick I/O is not
available on Linux.) Oracle will not be able to open the Quick I/O
files and the instance start up will fail. If you try to enable Quick
I/O on a file system mounted with the Concurrent I/O option, you
will receive an error message similar to the following:
ORA-01157: can not identify/lock datafile filename -
see DBWR \ trace file
ORA-01110: datafile filename:'/path_name/qio.f'
If the Quick I/O feature is availabe, do not use any Quick I/O tools
if the database is using Concurrent I/O.
See the (1M) manual page for more information about mount
settings.
Usage notes
To enable Concurrent I/O on a file system using mount with the -o cio option
Mount the file system using the mount command as follows:
# /usr/sbin/mount -F vxfs -o cio special /mount_point
where:
special is a block special device
/mount_point is the directory where the file system will be mounted.
117Using Veritas Concurrent I/O
Enabling and disabling Concurrent I/O