swaptab.5   [plain text]


.TH SWAPTAB 5 "March 1, 1989" "Apple Computer, Inc."
.SH NAME
swaptab \- static table of paging files
.SH SYNOPSIS
.B /etc/swaptab
.SH DESCRIPTION
The
.B /etc/swaptab
file contains entries for files that can be enabled for system
paging/swapping.  This file is read automatically by the
.BR mach_swapon (8)
command at system startup time.  If you change this file, the
changes will not take effect until the system is rebooted.
.PP
An entry for a paging file consists of a line of the following form:
.IP
.I file\ \ \ \fR[\fIoption\fR[\fB,\|\fIoption\fR]\|.\|.\|.] [\fB# \fIcomment\fR]
.TP 20
.I file
is the pathname of the file to page into
.TP
.I option
is one of:
.RS
.TP
.B prefer
Enable this file as a "preferred" paging area.  The system will
preferentially allocate space in this paging file over non-preferred
paging files.
.TP
.B noauto
Do not enable this file when
.B mach_swapon -a
is called.
.TP
.BI lowat= size
Attempt to shrink the file down to the low water mark,
.IR size ,
when paging resources are freed.  If
.I size
equals zero, then the paging file does not shrink as resources
are freed.
.TP
.BI hiwat= size
Do not grow the paging file above the high water mark,
.IR size .
If
.I size
is zero then the file will grow as large as needed.
.TP
.B nocompress
Do not compress the swapfile.  Normally, the swapfile is compressed, resulting in reduced disk usage and increased swapping performance (there is less to swap).  This option will turn this feature off.
.RE
.TP
.I comment
Anything preceded by a
.RB "# "
is ignored.
.SH EXAMPLE
.LP
.ta 0.8i 1.6i 2.4i 3.2i 4.0i
.nf
#
#	/etc/swaptab
#
/private/vm/swapfile	lowat=20971520	# 20 Meg low water mark
.fi
.br
.ne 6
.SH FILES
.PD 0
.TP 20
.B /etc/swaptab
.PD
.SH "SEE ALSO"
.BR mach_swapon (2),
.BR mach_swapon (8)
.SH WARNINGS
Entries beginning with whitespace will be ignored.