Operating system crash

TROUBLESHOOTING boot problems:

      a.) Entry_init status= -4 (Unrecoverable H/W error)
            * Booting from wrong disk
            * Bad LIF area (rebuild using support media)
            * Bad hard disk or other hardware issue
                  
      b.) Bad LIF magic
            * Booting from wrong disk
            * Bad LIF area (rebuild using support media)
            * Bad hard disk or other hardware issue

      c.) stand/vmunix: cannot open or not executable
            * Get to isl and run the command hpux ls -l / (does vmunix exist)
                             NOTE: If it doesn't exist then use support media
            * Try hpux /stand/vmunix.prev from isl
            
      d.) If system hangs after the kernel loads or panics
            * Try booting in single user mode (hpux -is)
            * Try booting in maintenance mode (hpux -lm)
                  NOTE: activate vg00 and see what happens.
            * Try hpux /stand/vmunix.prev

      e.) init: warning: bad shell "/usr/bin/ksh" for root
            * mount /usr and /var and vi /etc/passwd and fix the root line and
               change it to /sbin/sh.
            * check permissions on /etc/passwd (444 root:sys)

      f.) init: command respawning to rapidly
            * check /etc/rc.config.d for a file that doesn't belong in the
               directory or an incorrect modification to an existing file.
               Add the following to the top of the /etc/rc.config script:
                               set -x then execute the script {. /etc/rc.config}
                  NOTE: Need to boot to single user mode.

      g.) System boots in single user mode
            * Check /etc/inittab file (1st line -> init:3:initdefault:)
            * Check the AUTO file (lifcp /dev/rdsk/cxtxdx:AUTO -)