UPDATE(8)

NAME
update - flush internal filesystem caches to disk frequently

SYNOPSIS
update [normal_interval [save_energy_interval]]

DESCRIPTION
The update command helps protect the integrity of disk volumes by flushing volatile cached filesystem data to disk at thirty second intervals. Update uses the sync(2) function call to do the task. The normal_interval and save_energy_interval 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 AT&T UNIX.