Veritas Storage Foundation 5.1 SP1 Advanced Features Administrator"s Guide (5900-1503, April 2011)

An example to show how to create a 100MB Quick I/O-capable file named dbfile
on the VxFS file system /db01 using a relative path name:
$ /opt/VRTS/bin/qiomkfile -s 100m /db01/dbfile
$ ls -al
-rw-r--r-- 1 db2inst1 db2iadm1 104857600 Oct 2 13:42 .dbfile
lrwxrwxrwx 1 db2inst1 db2iadm1 19 Oct 2 13:42 dbfile -> \
.dbfile::cdev:vxfs:
In the example, qiomkfile creates a regular file named /db01/dbfile, which has
the real space allocated. Then, qiomkfile creates a symbolic link named
/db01/dbfile. This symbolic link is a relative link to the Quick I/O interface for
/db01/.dbfile, that is, to the .dbfile::cdev:vxfs: file. The symbolic link allows
.dbfile to be accessed by any database or application using its Quick I/O
interface.
We can then add the file to the DB2 database PROD:
$ db2 connect to PROD
$ db2 create tablespace NEWTBS managed by database using \
( DEVICE '/db01/dbfile' 100m )
$ db2 terminate
Preallocating space for Quick I/O files using the setext
command
As an alternative to using the qiomkfile command, you can also use the VxFS
setext command to preallocate space for database files.
Before preallocating space with setext, make sure the following conditions have
been met:
■ The setext command requires superuser (root) privileges.Prerequisites
■ You can use the chown command to change the owner and group
permissions on the file after you create it.
See the setext (1M) manual page for more information.
Usage notes
Improving DB2 performance with Veritas Quick I/O
Preallocating space for Quick I/O files using the setext command
42