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InfoScale™ 9.0 Storage and Availability Management for DB2 Databases - AIX, Linux

Last Published: 2025-04-13

Product(s): InfoScale & Storage Foundation (9.0)

Platform: AIX,Linux

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:

Prerequisites	The setext command requires superuser (root) privileges.
Usage notes	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.

To create a Quick I/O database file using setext

Use the setext command to preallocate space for the file:

		# /opt/VRTS/bin/setext -r size -f noreserve -f chgsize  \
		.filename

Create a symbolic link to allow databases or applications access to the file using its Quick I/O interface:
```
		# ln -s .filename::cdev:vxfs: filename
```

Change the owner and group permissions on the file.

For example, for DB2:

		# chown user:group .filename

# chmod 660 .dbfile

For example, for Sybase:

		# chown sybase:sybase .filename

		# chmod 660 .filename

To access the mountpoint for the database:

For example, for /db01, create a container, preallocate the space, and change the permissions:

# cd /db01
# touch .dbfile
# /opt/VRTS/bin/setext -r 100M -f noreserve -f chgsize .dbfile
# ln -s .dbfile::cdev:vxfs: dbfile

For DB2:

# chown db2inst1:db2iadm1 .dbfile

# chmod 660 .dbfile

For Sybase:

# chown sybase:sybase .dbfile

# chmod 660 .dbfile