Veritas File System 5.0 Administrator's Guide (September 2006)

Note: When Quick I/O is enabled, you cannot create a regular VxFS file with a
name that uses the ::cdev:vxfs: extension. If an application tries to create a
regular file named xxx::cdev:vxfs:, the create fails. If Quick I/O is not available,
it is possible to create a regular file with the ::cdev:vxfs: extension, but this
could cause problems if Quick I/O is later enabled. Symantec advises you to reserve
the extension only for Quick I/O files.
About use restrictions
There are restrictions to using regular VxFS files as Quick I/O files.
The name xxx::cdev:vxfs: is recognized as a special name by VxFS only
when the following conditions are met:
VxFS with Quick I/O has a valid license
The regular file xxx is physically present on the VxFS file system
There is no regular file named xxx::cdev:vxfs: on the system
If the file xxx is being used for memory mapped I/O, it cannot be accessed as
a Quick I/O file.
An I/O fails if the file xxx has a logical hole and the I/O is done to that hole on
xxx::cdev:vxfs:.
The size of the file cannot be extended by writes through the Quick I/O
interface.
About creating a Quick I/O file using qiomkfile
The best way to make regular files accessible to the Quick I/O interface and
preallocate space for them is to use the qiomkfile command. Unlike the VxFS
setext command, which requires superuser privileges, any user who has read/write
permissions can run qiomkfile to create the files. The qiomkfile command has
five options:
Creates a symbolic link with an absolute path name for a specified file. The
default is to create a symbolic link with a relative path name.
-a
For Oracle database files to allow tablespace resizing. Extends the file size by
the specified amount.
-e
For Oracle database files. Creates a file with additional space allocated for the
Oracle header.
-h
Quick I/O for Databases
About creating a Quick I/O file using qiomkfile
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