swap – establish a swap file|
Swap establishes a file for the system to swap on. If file is
an existing file, it is used for system swap. If it does not exist,
a new file is created. If file is a directory, a unique file is
created in that directory on which to swap. The environment variable
swap is set to the full name of the resulting file. The number
available in the file or device must be at least the number of
swap blocks configured at system boot time. |
If a swap channel has already been set and no blocks are currently
valid in the file the old file will be closed and then replaced.
If any blocks are valid on the device an error is returned instead.
Swapping to a file served by a local user–level process will lead
to deadlock if the process isn't made non–swappable (see the noswap
ctl–message in proc(3)).|