Fixing Readonly filesystem issue

1. Login to the console
2. On console window, click on Device -> cd/DVD drive1 -> connect to disk image file (iso)
3. Reboot the system (ctrl+alt+del)
4. Click on the middle of the screen (super fast) and press esc to get the boot menu.
5. If you miss this step, reboot the system again.
6. On boot menu list, select cd-rom and press enter to reboot the system off the cdrom.
7. On the boot menu on the cd-rom, select rescue and press enter.
8. Just follow the instruction by pressing the enter key.
9. You will be on shell prompt.
10. Now, mount your system and find your readonly filesystem. (mostly root fs.)
# chroot /mnt/sysimage; df -h /
Note: at this point you can change your root pw if you needed
# mount -o rw,remount /; passwd
11. Exit out off the OS and unmount your system disk
# exit; umount -l /mnt/sysimage
12. fsck all the filesystem to fix the issue.
# fsck -y /dev/rootvg/rootVol
13. Once done, reboot your system.
14. Login and verify if everything is working.