UPDATE(1) General Commands Manual UPDATE(1)NAMEupdate - periodically write the buffer cache to diskSYNOPSISupdateEXAMPLESupdate & # Start a process that flushes the cacheDESCRIPTIONWhen the system is booted, update is started up in the background from /etc/rc to issue a SYNC system call every 30 sec.SEE ALSOboot(8). UPDATE(1)