.TH UPDATE 8 .SH NAMEupdate \- periodically update the super block.SH SYNOPSIS.B /etc/update.SH DESCRIPTION.I Updateis a program that executesthe.IR sync (2)primitive every 30 seconds.This insures that the file systemis fairly up to date in case of a crash.This command should not be executed directly,but should be executed out of theinitialization shell command file..SH "SEE ALSO"sync(2), sync(1), init(8).SH BUGSWith.I updaterunning,if the CPU ishalted just asthe.I syncis executed,a file system can be damaged.This is partially due to DEC hardware thatwrites zeros when NPR requests fail.A fix would be to have.IR sync (1)temporarily increment the system time by atleast 30 seconds to trigger the execution of.I update.This would give 30 seconds grace to halt the CPU.