.TH UPDATE 1 .SH NAME update \- periodically write the buffer cache to disk .SH SYNOPSIS \fBupdate\fR .br .de FL .TP \\fB\\$1\\fR \\$2 .. .de EX .TP 20 \\fB\\$1\\fR # \\$2 .. .SH EXAMPLES .EX "update &" "Start a process that flushes the cache" .SH DESCRIPTION .PP When the system is booted, .I update is started up in the background from .I /etc/rc to issue a \&SYNC system call every 30 sec. .SH "SEE ALSO" .BR boot (8).