Veritas Storage Foundation™ for Oracle 5.0.1 Administrator's Guide

in OLTP throughput when using indirect extent access. In addition, this type of

preallocation causes no fragmentation of the file system.

You must preallocate Quick I/O files because they cannot be extended through

writes using their Quick I/O interfaces. They are initially limited to the maximum

size you specify at the time of creation.

See “Extending a Quick I/O file” on page 94.

About Quick I/O naming conventions

VxFS uses a special naming convention to recognize and access Quick I/O files as

raw character devices. VxFS recognizes the file when you add the following

extension to a file name:

::cdev:vxfs:

Whenever an application opens an existing VxFS file with the extension

::cdev:vxfs: (cdev being an acronym for character device), the file is treated as

if it were a raw device. For example, if the file temp01 is a regular VxFS file, then

an application can access temp01 as a raw character device by opening it with the

name:

.temp01::cdev:vxfs:

Note: We recommend reserving the ::cdev:vxfs: extension only for Quick I/O

files. If you are not using Quick I/O, you could technically create a regular file

with this extension; however, doing so can cause problems if you later enable

Quick I/O.

How to set up Quick I/O

Quick I/O is included in the VxFS package shipped with Veritas Storage Foundation

for Oracle. By default, Quick I/O is enabled when you mount a VxFS file system.

If Quick I/O is not available in the kernel, or the Veritas Storage Foundation for

Oracle license is not installed, a file system mounts without Quick I/O by default,

the Quick I/O file name is treated as a regular file, and no error message is

displayed. If, however, you specify the -o qio option, the mount command prints

the following error message and terminates without mounting the file system.

VxFDD: You don't have a license to run this program

vxfs mount: Quick I/O not available

Depending on whether you are creating a new database or are converting an

existing database to use Quick I/O, you have the following options:

Using Veritas Quick I/O

About Quick I/O