 -   <CONTROL+ALT+DEL>.)    -
    ,    SIGINT  init, -
   shutdown.   init    root,  -
 shutdown    root,      
.  <CONTROL+ALT+DEL>  ,  
    /etc/inittab (      #),   
 init  HUP (kill -HUP 1),      
/etc/inittab.

consolehelper:   
  

  ,     halt:

$ file /sbin/halt /usr/bin/halt

/shin/halt:    ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV)...
/usr/bin/halt: symbolic link to 'consolehelper'   ('   ...)

,     /sbin,   halt,   
/usr/bin    consolehelper.   PATH  root -
 /sbin    /usr/bin,     
root   halt,    /sbin/halt ( halt).  -
,  /sbin     PATH  ; 
    halt,     /usr/bin/halt
   /usr/bin/consolehelper.

  consolehelper      (.  /etc/pam.d/halt
     /usr/share/doc/pam-*/txts/*    -
).      ""    -
.    Red Hat  consolehelper  ,  -
  root,       .

   

       -
    ,      .
       
;      .

        , 
     .       -
 .

1.    wall ("write all"   )   -
  ,      .

2.       NFS   exportfs
-ua,         (
exportfs        ).

3.    umount -    
( mount      ).

4.   telinit 1,      .

 11.  :                     415