UPDATE(8)               GENIX Programmer's Manual               UPDATE(8)



      NAME
           update - periodically update the super block

      SYNOPSIS
           /etc/update

      DESCRIPTION
           Update is a program that executes the  sync(2)  primitive  every  30
           seconds.   This insures that the file system is fairly up to date in
           case of a crash.  This command should not be executed directly,  but
           should be executed out of the initialization shell command file.

      SEE ALSO
           sync(2), sync(1), init(8)

      BUGS
           With update running, if the CPU is halted just as the sync  is  exe-
           cuted,  a  file system can be damaged.  This is partially due to DEC
           hardware that writes zeros when NPR requests fail.  A fix  would  be
           to have sync(1) temporarily increment the system time by at least 30
           seconds to trigger the execution  of  update.  This  would  give  30
           seconds grace to halt the CPU.

































      Printed 11/16/83                                                        1