Boot block is damaged ...

Booting from CD-ROM to repair a Bad Boot Block

1. > b sd(0,6,2) -sw or
   ok boot cdrom -sw
   
2. # cd /usr/platform/`arch-k`/lib/fs/ufs
3. # installboot bootblk /dev/rdsk/c0t3d0s0
   (to install boot block to booting disk.
4. # halt
5. ok boot

Replacing the Kernel Unix File

1. ok boot cdrom -sw or
   ok boot sd(0.6.2) -sw
2. # mount /dev/dsk/c0t#d0s0 /a
3. # cp /kernel/unix /a/kernel/unix (or /kernel/genunix)
4. # halt
5. ok boot

Using vi Single-User Mode from the CD-ROM Files

1. ok boot cdrom -sw or
   ok boot sd(0,6,2) -sw
2. # mount /dev/dsk/c0t3d0s0 /a
   (/dev/dsk/c0t3d0s0 is booting disk)
3. # TERM=sun; export TERM
4. # vi /a/etc/vfstab (to modify the entry)
5. # reboot