Reset root and sys password

RESET LINUX root PASSWORD

METHOD 1
1. Boot the computer with Linux Installation CD.
2. Enter into Linux Rescue mode by enering the following command in boot screen. boot: linux rescue
3. When the sh prompt is reached, enter the following commands to change root password.

#chroot /mnt/sysimage
#passwd

METHOD 2
1. When u reached at the grub screen press 'e' on linux which contains the word 'kernell' press 'e'
2. Go to end of that line and write 'linux single'
3. Then press 'esc' twice and press 'b' to reboot the system
4. Now wait for the prompt and type the following command to reset the password for root

#passwd root

The above steps will prompt you to enter your new password.

RESET ORACLE sys USER PWD

Your password file should be under \database\PWD.ora.
Delete it and run the Oracle password utility from the command prompt as;

#orapwd file=pwdSID.ora password=newpassword entries=enterAnumber

The is your new sys password. After you log in as sys you can change it and create new passwords for system etc