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SWAPON(2) | System Calls Manual | SWAPON(2) |
NAME¶
swapon
,
swapoff
—
control devices for interleaved paging/swapping
LIBRARY¶
Standard C Library (libc, -lc)SYNOPSIS¶
#include
<unistd.h>
int
swapon
(const
char *special);
int
swapoff
(const
char *special);
DESCRIPTION¶
Theswapon
() system call makes the block
device special available to the system for
allocation for paging and swapping. The names of potentially available devices
are known to the system and defined at system configuration time. The size of
the swap area on special is calculated at the
time the device is first made available for swapping.
The swapoff
() system call disables paging and
swapping on the given device. All associated swap metadata are deallocated,
and the device is made available for other purposes.
RETURN VALUES¶
If an error has occurred, a value of -1 is returned and errno is set to indicate the error.ERRORS¶
Bothswapon
() and
swapoff
() can fail if:
- [
ENOTDIR
] - A component of the path prefix is not a directory.
- [
ENAMETOOLONG
] - A component of a pathname exceeded 255 characters, or an entire path name exceeded 1023 characters.
- [
ENOENT
] - The named device does not exist.
- [
EACCES
] - Search permission is denied for a component of the path prefix.
- [
ELOOP
] - Too many symbolic links were encountered in translating the pathname.
- [
EPERM
] - The caller is not the super-user.
- [
EFAULT
] - The special argument points outside the process's allocated address space.
swapon
() can fail for the
following reasons:
- [
ENOTBLK
] - The special argument is not a block device.
- [
EBUSY
] - The device specified by special has already been made available for swapping
- [
ENXIO
] - The major device number of special is out of range (this indicates no device driver exists for the associated hardware).
- [
EIO
] - An I/O error occurred while opening the swap device.
swapoff
() can fail if:
- [
EINVAL
] - The system is not currently swapping to special.
- [
ENOMEM
] - Not enough virtual memory is available to safely disable paging and swapping to the given device.
SEE ALSO¶
config(8), swapon(8), sysctl(8)HISTORY¶
Theswapon
() system call appeared in
4.0BSD. The
swapoff
() system call appeared in
FreeBSD 5.0.October 4, 2013 | Debian |