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28 .\" @(#)swapon.8 8.1 (Berkeley) 6/5/93
35 .Nm swapon , swapoff , swapctl
36 .Nd "specify devices for paging and swapping"
39 .Nm swapoff Fl aq | Ar
52 utilities are used to control swap devices in the system.
53 At boot time all swap entries in
55 are added automatically when the system goes multi-user.
56 Swap devices use a fixed interleave; the maximum number of devices
57 is specified by the kernel configuration option
59 which is typically set to 4.
60 There is no priority mechanism.
64 utility adds the specified swap devices to the system.
67 option is used, all swap devices in
69 will be added, unless their
74 option is used informational messages will not be
75 written to standard output when a swap device is added.
79 utility removes the specified swap devices from the system.
82 option is used, all swap devices in
84 will be removed, unless their
89 option is used informational messages will not be
90 written to standard output when a swap device is removed.
93 will fail and refuse to remove a swap device if there is insufficient
94 VM (memory + remaining swap devices) to run the system.
98 must move swapped pages out of the device being removed which could
99 lead to high system loads for a period of time, depending on how
100 much data has been swapped out to that device.
104 utility exists primarily for those familiar with other
107 used to add, remove, or list swap devices.
110 option is used differently in
112 and indicates that a specific list of devices should be added.
115 option indicates that a specific list should be removed.
122 operate on all swap entries in
124 which do not have their
128 Swap information can be generated using the
138 utility has the following options for listing swap:
139 .Bl -tag -width indent
141 Output values in human-readable form.
143 Output values in gigabytes.
145 Output values in kilobytes.
147 Output values in megabytes.
149 List the devices making up system swap.
151 Print a summary line for system swap.
155 environment variable is used if not specifically
157 512 byte blocks are used by default.
160 .Bl -tag -width ".Pa /dev/{ad,da}?s?b" -compact
161 .It Pa /dev/{ad,da}?s?b
162 standard paging devices
167 file system description table
170 These utilities may fail for the reasons described in
188 utilities appeared in