Technical Reference: Base Operating System and Extensions , Volume 2

swapon Subroutine

Purpose

Activates paging or swapping to a designated block device.

Library

Standard C Library (libc.a)

Syntax

#include <sys/vminfo.h>

int swapon ( PathName) char *PathName;

Description

The swapon subroutine makes the designated block device available to the system for allocation for paging and swapping.

The specified block device must be a logical volume on a disk device. The paging space size is determined from the current size of the logical volume.

Parameters

PathName

Specifies the full path name of the block device.

Error Codes

If an error occurs, the errno global variable is set to indicate the error:

EINTR	Signal was received during processing of a request.
EINVAL	Invalid argument (size of device is invalid).
ENOENT	The PathName file does not exist.
ENOMEM	The maximum number of paging space devices (16) are already defined, or no memory is available.
ENOTBLK	Block device required.
ENOTDIR	A component of the PathName prefix is not a directory.
ENXIO	No such device address.

Other errors are from calls to the device driver's open subroutine or ioctl subroutine.

Implementation Specifics

This subroutine is part of Base Operating System (BOS) Runtime.

Related Information

The swapoff subroutine,swapqry subroutine.

The swapoff command, swapon command.

The Subroutines Overview in AIX 5L Version 5.1 General Programming Concepts: Writing and Debugging Programs.