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4. | Chapter 3 # Backing Out the Solaris 9 Maintenance Update 2 If you need to remove one of the patches, you can do so. However, you must not have used the `-d` option of `install_mu` during the installation of the Solaris 9 MU2 software. Instructions for backing out individual patches are located in each patch directory. Patch directories are located in `/var/sadm/patch/`. Note - Backing out the entire MU is not possible if you selected the `-d` option of `install_mu`. # Backing Out the Solaris 9 MU2 Ideally, you reboot your system in single-user mode before backing out the MU2. MU2 applies patches to system libraries. Avoid introducing instability in individual systems in a multiuser system. Ensure that no processes have mapped to a patched version of a library. Otherwise, those processes might later attempt to map to different sections of the old library. In single-user mode, network services are not available. You must copy the MU2 image from the network to your local system before booting your system in single-user mode. You need to backout MU2 by using NFS in multiuser mode if you meet one fo the following conditions: You cannot reboot the system in single-user mode You do not have enough disk space to make a local copy of the MU2 image The `backout_mu` script that is provided by MU2 enables you to back out an entire MU. To back out the Solaris 9 MU2 software: Ensure that no important user or system processes are running. Exit the current session. The CDE login screen is displayed. Click the Options button and select Command Line Login. The system prompts you to log in. Type your login name as root and type the root password:
       login: root
       password: root password
5. Reboot in single-user mode. From the root shell prompt, type:
       # reboot -- -s
6. Type the root password. Check that the system displays the following message and is now in system maintenance mode.
       Entering System Maintenance Mode

       Sun Microsystems Inc. SunOS 5.9 Generic May 2002
       #
7. Run `backout_mu`. From a local copy of the MU2 image, type:
       # cd local_directory
       # ./backout_mu options
   Table 3-1 Command-Line Options for `backout_mu`
   Option | Description
   --- | ---
   `-q` | Disables the display of dots that indicate `backout_mu` activity
   `-B` backoutdir | Specifies an alternate directory for storing the information that is required to back out a patch
8. When the backout is complete, check that the following message is displayed.
       backout_mu completed at date_time.
9. If you see this message, go to Step 9 to complete the backout. If you encounter any errors, go to Chapter 5, Error Messages. Reboot the system by typing:
       # sync ; reboot
10. You are then prompted for a login. Note - To prevent the library conflict problem, you must reboot your system after backing out MU2. Type your login name and password:
        login: login
        password: password