If you have to fsck on Solaris 8 and up:


   fsck -F ufs -Y /dev/dsk/c0t0d0s0


to mount a file system onto a cdrom (let's say for example
that you messed up the root account on your system in a class... )

   <stop> A 

- insert install CDROM

    boot cdrom -s
    
    fsck -F ufs -Y /dev/dsk/c0t0d0s0

    mount /dev/dsk/c0t0d0s0 /a

corrupt /usr - run fsck manually:

    fsck -F ufs -Y /dev/dsk/c0t0d0s6  (to fix /usr)

once the file systems are clean, then:

    vi /etc/passwd  

NOTE:  do NOT set root's shell to ksh, make sure it's set to /sbin/sh