UPDATE(8)                 BSD System Manager's Manual                UPDATE(8)

NAME
     update -- flush internal filesystem caches to disk frequently

SYNOPSIS
     update [normalinterval [saveenergyinterval]

DESCRIPTION
     The update command helps protect the integrity of disk volumes by flush-
     ing volatile cached filesystem data to disk at thirty second intervals.
     Update uses the sync(2) function call to do the task.  The normalinter-
     val and saveenergyinterval can be used to set the sync(2) interval in
     seconds of the normal case and the case where the computer is trying to
     save energy.

     Update is commonly invoked at startup time by rc(8) when the system goes
     multi-user.

SEE ALSO
     sync(2), fsck(8), init(8), rc(8), sync(8)

BUGS
     It is possible on some systems that a sync occurring simultaneously with
     a crash may cause file system damage. See fsck(8).

HISTORY
     An update command appeared in Version 6 AT&T UNIX.

BSD                             April 19, 1994                             BSD