update.tproj/update.8

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  32 .\"     @(#)update.8    8.3 (Berkeley) 4/19/94
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  34 .Dd April 19, 1994
  35 .Dt UPDATE 8
  36 .Os
  37 .Sh NAME
  38 .Nm update
  39 .Nd flush internal filesystem caches to disk frequently
  40 .Sh SYNOPSIS
  41 .Nm update
  42 .Sh DESCRIPTION
  43 The
  44 .Nm update
  45 command helps protect the integrity of disk volumes
  46 by flushing
  47 volatile cached filesystem data
  48 to disk at thirty second intervals.
  49 .Nm Update
  50 uses the
  51 .Xr sync 2
  52 function call to do the task.
  53 .Pp
  54 .Nm Update
  55 is commonly invoked at startup time by
  56 .Xr rc 8
  57 when the system goes multi-user.
  58 .Sh SEE ALSO
  59 .Xr sync 2 ,
  60 .Xr fsck 8 ,
  61 .Xr init 8 ,
  62 .Xr rc 8 ,
  63 .Xr sync 8
  64 .Sh BUGS
  65 It is possible on some systems that a
  66 .Xr sync
  67 occurring simultaneously with a crash may cause
  68 file system damage. See
  69 .Xr fsck 8 .
  70 .Sh HISTORY
  71 An
  72 .Nm update
  73 command appeared in
  74 .At v6 .