swapon (8) ( FreeBSD man: Команды системного администрирования )
swapon (8) ( Linux man: Команды системного администрирования )
BSD mandoc
NAME
swapon , swapoff
- control devices for interleaved paging/swapping
LIBRARY
Lb libc
SYNOPSIS
#include <unistd.h> int
swapon (const char *special); int
swapoff (const char *special);
DESCRIPTION
The
swapon ();
system call
makes the block device
Fa 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
Fa 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
Both
swapon ();
and
swapoff ();
can fail if:
Bq Er ENOTDIR
A component of the path prefix is not a directory.
Bq Er ENAMETOOLONG
A component of a pathname exceeded 255 characters,
or an entire path name exceeded 1023 characters.
Bq Er ENOENT
The named device does not exist.
Bq Er EACCES
Search permission is denied for a component of the path prefix.
Bq Er ELOOP
Too many symbolic links were encountered in translating the pathname.
Bq Er EPERM
The caller is not the super-user.
Bq Er EFAULT
The
Fa special
argument
points outside the process's allocated address space.
Additionally,
swapon ();
can fail for the following reasons:
Bq Er EINVAL
The system has reached the boot-time limit on the number of
swap devices,
vm.nswapdev
Bq Er ENOTBLK
The
Fa special
argument
is not a block device.
Bq Er EBUSY
The device specified by
Fa special
has already
been made available for swapping
Bq Er ENXIO
The major device number of
Fa special
is out of range (this indicates no device driver exists
for the associated hardware).
Bq Er EIO
An I/O error occurred while opening the swap device.
Lastly,
swapoff ();
can fail if:
Bq Er EINVAL
The system is not currently swapping to
Fa special .
Bq Er ENOMEM
Not enough virtual memory is available to safely disable
paging and swapping to the given device.
