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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"
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
75 utility removes the specified swap devices from the system.
78 option is used, all swap devices in
80 will be removed, unless their
85 will fail and refuse to remove a swap device if there is insufficient
86 VM (memory + remaining swap devices) to run the system.
90 must move swapped pages out of the device being removed which could
91 lead to high system loads for a period of time, depending on how
92 much data has been swapped out to that device.
96 utility exists primarily for those familiar with other
99 used to add, remove, or list swap devices.
102 option is used differently in
104 and indicates that a specific list of devices should be added.
107 option indicates that a specific list should be removed.
114 operate on all swap entries in
116 which do not have their
120 Swap information can be generated using the
130 utility has the following options for listing swap:
131 .Bl -tag -width indent
133 Output values in megabytes.
135 Output values in kilobytes.
137 List the devices making up system swap.
139 Print a summary line for system swap.
143 environment variable is used if not specifically
145 512 byte blocks are used by default.
148 .Bl -tag -width ".Pa /dev/{ad,da}?s?b" -compact
149 .It Pa /dev/{ad,da}?s?b
150 standard paging devices
155 file system description table
158 These utilities may fail for the reasons described in
176 utilities appeared in