shutdown

PURPOSE

     Ends system operation.

SYNOPSIS
     shutdown [ -m ] [ -v ] [ seconds ]

     shutdown [ -f ]

DESCRIPTION

     The shutdown command brings the AIX Operating System from
     distributed mode  to multiuser mode, from  multiuser mode
     to maintenance  mode, or halts the  operating system com-
     pletely by  shutting down  the virtual machine.   You can
     run shutdown only if you are a member of the system group
     or if you have superuser authority.

     During  the default  shutdown, users  are notified  (by a
     wall command)  of the impending system  shutdown with the
     message:  "THE SYSTEM IS  COMING DOWN NOW".  However, the
     shutdown  is not  complete  until the  user receives  the
     message: "...shutdown  completed...".  Do not  attempt to
     reboot the system (Ctrl-Alt-Pause) or turn off the system
     before this message is  displayed; otherwise, file system
     damage may result.

     During the  shutdown, the  hold command prevents  any new
     logins.   After the  specified number  of seconds  (60 by
     default),  the system  stops  the  accounting and  error-
     logging  processes.   shutdown   then  runs  the  killall
     command to end any remaining  processes and runs the sync
     command  to  flush  all   memory  resident  disk  blocks.
     Finally,  it  unmounts the  file  systems  and sends  the
     appropriate signal to init.  These signals are:

     sigint    Maintenance mode
     sigterm   Virtual machine halt.

     Note:   Users who  have files  open on  the node  that is
     running shutdown, but who are not logged on that node are
     not notified about the shutdown.

     If there are no other users on the system and you want to
     shutdown the system quickly, you may want to use shutdown
     -f.  This  option bypasses  messages to users  and brings
     the system down as quickly as possible.

     If you request  a complete halt to  the operating system,
     shutdown kills all processes,  unmounts all file systems,
     and sends init the sigterm signal.

     Warning:  If you are bringing  the system down to mainte-
     nance mode, you must run shutdown from the root directory
     to ensure that it can cleanly unmount the file systems.

FLAGS

     -d Brings the  system down from  a distributed mode  to a
        multiuser mode.
     -f Does a fast shutdown,  bypassing the messages to other
        users and bringing the system  down as quickly as pos-
        sible.   If you  do  not specify  this flag,  shutdown
        sends a  message to  each logged-in  user and  waits a
        certain  amount of  time  before  bringing the  system
        down, to allow each user to log off cleanly.
     -m Brings  the system  down  to  maintenance mode.   From
        maintenance mode, you can return to multi-user mode.
     -v Shuts down  the virtual  machine (halts  the operating
        system completely).

EXAMPLES

     1.  To tell  the operating system  you are about  to turn
         off the machine:

           shutdown

         This shuts down the system, waiting 60 seconds before
         stopping the user processes and the init process.
     2.  To give users and the system more time to finish what
         they are doing:

           shutdown  -m  120  *

         This brings  the system  down from multiuser  mode to
         maintenance mode after waiting 120 seconds.

FILES

     /etc/shutdown.sh
     /etc/fshutdown.sh

RELATED INFORMATION

     The  following  commands:  "acct,"   "errstop,"  "init,"
     "kill," and "killall,"

     The  dsstate and  signal  system calls  in AIX  Operating
     System Technical Reference.