dynamic_pager.tproj/dynamic_pager.8

   1 .\" Copyright (c) 2003 Apple Computer, Inc.  All rights reserved.
   2 .\"
   3 .Dd July 8, 2003
   4 .Dt dynamic_pager 8
   5 .Os "Mac OS X"
   6 .Sh NAME
   7 .Nm dynamic_pager
   8 .Nd external storage manager for dynamic pager
   9 .Sh SYNOPSIS
  10 .Nm dynamic_pager
  11 .Op Fl E
  12 .Op Fl F Ar filename
  13 .Op Fl S Ar filesize
  14 .Op Fl H Ar high-water-trigger
  15 .Op Fl L Ar low-water-trigger
  16 .Op Fl P Ar priority
  17 .Sh DESCRIPTION
  18 The
  19 .Nm dynamic_pager
  20 daemon manages a pool of external swap files
  21 which the kernel uses to support demand paging.
  22 This pool is expanded with new swap files
  23 as load on the system increases.
  24 It is contracted when the swapping resources are no longer needed.  The
  25 .Nm dynamic_pager
  26 daemon also provides a notification service
  27 for those applications which wish to receive notices
  28 when the external paging pool expands or contracts.
  29 .Sh OPTIONS
  30 .Bl -tag -width Ds
  31 .\" ==========
  32 .It Fl E
  33 Encrypt the data in the swap files.
  34 .\" ==========
  35 .It Fl F
  36 The base name of the
  37 .Ar filename
  38 to use for the external paging files.  By default this is
  39 .Pa /private/var/vm/swapfile .
  40 .\" ==========
  41 .It Fl H
  42 If there are less than
  43 .Ar high-water-trigger
  44 bytes free in the external paging files, the kernel will signal
  45 .Nm dynamic_pager
  46 to add a new external paging file.
  47 .\" ==========
  48 .It Fl L
  49 If there are more than
  50 .Ar low-water-trigger
  51 bytes free in the external paging files, the kernel will coalese in-use pages
  52 and signal
  53 .Nm dynamic_pager
  54 to discard an external paging file.
  55 .Ar Low-water-trigger
  56 must be greater than
  57 .Ar high-water-trigger
  58 +
  59 .Ar filesize .
  60 .\" ==========
  61 .It Fl P
  62 This option is currently unimplemented.
  63 .\" ==========
  64 .It Fl S
  65 The fixed
  66 .Ar filesize
  67 [in bytes] to use for the paging files.  By default
  68 .Nm dynamic_pager
  69 uses variable sized paging files, using larger sized files as paging demands
  70 increase.  The
  71 .Fl S ,
  72 .Fl H
  73 and
  74 .Fl L
  75 options disable that default and cause
  76 .Nm dynamic_pager
  77 to use a series of fixed sized external paging files.
  78 .El
  79 .Sh FILES
  80 .Bl -tag -width /private/var/vp/swapfile* -compact
  81 .It Pa /private/var/vm/swapfile*
  82 Default external paging files.
  83 .El