4 Patch Installation and Removal Instructions

This chapter provides instructions for installing and removing patches from the Tru64 UNIX operating system and the TruCluster software products.

Note

Chapter 5 describes the procedure for patching a TruCluster Server Version 5.0A or higher cluster using the rolling upgrade function. If you are patching your system with that process, follow the steps described in Chapter 5, and then return to this chapter for help in running the dupatch utility.
If you have not yet created your cluster, follow the steps in Section 3.3.

4.1 Summary of Steps for Using Patch Kits

The following list summarizes the steps necessary to install patches on your system. The referenced sections provide the full details. Compaq recommends that you familiarize yourself with these steps before attempting to install Tru64 UNIX or TruCluster software patch kits.

Review the list of issues and restrictions in Chapter 3 and in the Patch Summary and Release Notes document that comes with your patch kit.

Prepare your system for patch installation (Section 4.2).

Make the patch distribution available to your system (Section 4.3).

Load any new patch tools provided with the new patch distribution (Section 4.4).

Set the patch baseline if system files have been changed manually (Section 4.7).

Perform patch preinstallation check (Section 4.6).

Install patches mode (Section 4.8).

Rebuild the kernel and reboot the system (Section 4.9).

4.2 Preparing to Install Patches

Before using the latest Tru64 UNIX or TruCluster software patch distribution, make sure that your system meets the required criteria and that you perform certain preinstallation tasks, as described in the following list:

Make sure you have the correct software
You must have the appropriate versions of Tru64 UNIX and TruCluster software installed on your system to install patch kits. There are separate patch kits for each version of the Tru64 UNIX and TruCluster software products. The patch kits will not install on any other version of those products. For example, the Tru64 UNIX 5.0 patch kit will only install on Tru64 UNIX Version 5.0.

Back up your system
It is recommended that you backup your /, /usr, and /var file systems prior to installing patches or baselining your system.

Make sure you have enough storage space
Refer to the Patch Summary and Release Notes for the required storage space.

4.3 Making the Patch Distribution Available

Tru64 UNIX and TruCluster software patches are available from the Compaq Services Web page or the Tru64 UNIX Patch CD-ROM. Once you have obtained the patch distributions use the following instructions to make the patch kits available to the system targeted for update:

Ensure the installation prerequisites described in Section 4.2 are met.

If you are using patch tar files obtained via the Internet from Compaq (see Section 1.4), you must expand the tar file to access the patch kits. The tar file can be expanded on any NFS mountable file system. For example:
```
# /usr/sbin/mount /dev/disk/dsk3g /PatchKits
# cd /PatchKits  
# mkdir kit2
```
Copy or ftp the patch kit to /PatchKits/kit2. For example:
```
# cp T64V50AS0002-20000324.tar  /PatchKits/kit2
# script untar.log
# tar -xpvf T64V50AS0002-20000324.tar
# [Ctrl/d]
```
Or alternatively:
```
# exit
```
View the untar.log for errors or failures untarring the file.
Once the tar file has been expanded, make the file system containing the patch kits available to the system being patched. For example, on the system you are patching do the following:
```
# /usr/sbin/mount /PatchKits/kit2@hostname /mnt
```

If you are using the Tru64 UNIX Patch CD-ROM you need only mount the CD-ROM, as the information on the CD-ROM is already expanded. For example:
```
# usr/sbin/mount -r /dev/disk/cdrom0c /mnt
```

4.4 Loading New Patch Tools

The patch kits deliver updated patch tools to your system. It is important that you run the dupatch utility located in the /patch_kit directory every time you obtain new patch tar files or a new Tru64 UNIX Patch CD-ROM.

After you have made the patch kits available to the system being patched, run dupatch as follows:

# /mnt/PatchKits/kit2/patch_kit/dupatch

If new patch tools are available they will be loaded and you will see messages similar to the following:

   * A new version of patch tools required for patch management
     is now being installed on your system.
 
   * Tools updated, invoking the updated Patch Utility...

The dupatch utility saves information on the tools that have been loaded to the log file /var/adm/patch/log/Dupatch_load_date.log. (See Section 2.2 for information about log files.)

4.5 Invoking the Main dupatch Menu

Once the new tools have been loaded, dupatch prompts you for the path to the patch kit files. After you specify the path (or press Return if the patch kit is your current directory) you will see the main menu. For example:

Enter path to the top of the patch distribution,
or enter "q" to get back to the menu : /mnt/PatchKit/kit2/patch_kit
 
Tru64 UNIX Patch Utility (Rev. 29-01)
==========================
	- This dupatch session is logged in /var/adm/patch/log/session.log
 
    Main Menu:
    ---------
 
    1)  Patch Installation
    2)  Patch Deletion
 
    3)  Patch Documentation
    4)  Patch Tracking
 
    5)  Patch Baseline Analysis/Adjustment
 
    h)  Help on Command Line Interface
 
    q)  Quit
 
Enter your choice:

4.6 Performing Patch Preinstallation Check Instructions

To minimize system down time, you can perform the preinstallation check on a system running in multiuser mode, even if you will perform the actual installation in single-user mode.

Note that the menu you see will differ slightly, depending upon whether you log in from a pseudo-terminal or a system console. The following steps assume you logged in from a pseudo-terminal.

Log in as root.

From the main dupatch menu, enter 1 at the Enter your choice prompt:

Tru64 UNIX Patch Utility (Rev. 29-01)
==========================
	- This dupatch session is logged in /var/adm/patch/log/session.log
 
    Main Menu:
    ---------
 
    1)  Patch Installation
    2)  Patch Deletion
 
    3)  Patch Documentation
    4)  Patch Tracking
 
    5)  Patch Baseline Analysis/Adjustment
 
    h)  Help on Command Line Interface
 
    q)  Quit
 
Enter your choice: 1

The program responds with the Patch Installation Menu. Enter 1 at the Enter your choice prompt:

 Tru64 UNIX Patch Utility (Rev. 29-01)
         ==========================
             - This dupatch session is logged in /var/adm/patch/log/session.log
 
             Patch Installation Menu:
             ------------------------
 
             1)  Pre-Installation Check ONLY
             2)  Check & Install in single-user mode w/ network services
             3)  Check and Install in Multi-User mode
 
 
             b) Back to Main Menu
             q) Quit
 
         Enter your choice: 1
 
Checking patch kit for transmission errors during download...
 
Finished Checking patch kit checksums
 
Gathering patch information...
  (depending upon the size of the patch kit, this may take awhile)
 
 
                ***  Start of Special Instructions  ***
 
 
 
 
                ***  There are NO Special Instructions  ***
 
 
 
	Press RETURN to proceed...

You have the option to make the patches reversible so you can revert the system to its state prior to the installation of a patch. The dupatch utility lists the following information. Press Return at the prompt to make the patches reversible. This is the recommended action.

     ------------------------------------------------------------------------
 
     To Make Patches Reversible - PLEASE READ THE FOLLOWING INFORMATION:
 
 
   - You have the option to make the patches reversible so you can 
     revert the system to its state prior to the installation of a patch.  
 
   - Reversibility is achieved by compressing and saving a copy of the 
     files being replaced by the patches. These files would be restored 
     to the system if you choose to delete a patch.
 
   - If you choose to make patches NON-reversible, then the system cannot 
     be restored to the state prior to the installation of a patch; you 
     will not be able to delete the patches later.
 
   - This patch kit may force a small set of patches to be reversible to 
     ensure your upgrades to future versions of Tru64 UNIX are successful. 
     The Patch Utility will make those patches reversible automatically. 
 
     Refer to the Release Notes / Installation Instructions provided with
     this patch kit.
 
Do you want the patches to be reversible? [y]: [Return]
 
     By default, the backup copies of the installed patches will be saved in
     "/var/adm/patch/backup".
 
     If you have limited space in /var, you may want to make the backup
     directory the mount point for a separate disk partition, an NFS mounted
     directory, or a symbolic link to another file system.
 
     You must ensure the backup directory is configured the same way during
     any patch removal operations.
 
Your current setup of "/var/adm/patch/backup" is:
 
	* A plain directory (not a mount point or a symbolic link) 
        Do you want the patches to be reversible? [y]: [Return]

By default, the backup copies of the installed patches will be saved in /var/adm/patch/backup. If you have limited space in /var, you may want to make the backup directory the mount point for a separate disk partition, an NFS mounted directory, or a symbolic link to another file system.

Answer yes when asked if you want to perform the preinstallation check with this setup:

Do you want to proceed with the pre-installation check with this setup? [y]:

The program then lists the patches that apply to your system. Compaq recommends that you install all of these patches. For example:

The patches listed below are optional:
 
     There may be more optional patches than can be presented on a single
     screen. If this is the case, you can choose patches screen by screen
     or all at once on the last screen. All of the choices you make will
     be collected for your confirmation before any patches are installed.
 
 - Tru64_UNIX_V5.0A / Cluster Kernel Patches:
     1) Patch 00090.00 - versw command can core dump during rolling upgrade     
     2) Patch 00186.00 - Disks can become inaccessible on a cluster node        
 
 - Tru64_UNIX_V5.0A / Commands, Shells, & Utilities Patches:
     3) Patch 00015.00 - Fixes a problem that occurs in multibyte locales       
     4) Patch 00019.00 - Fixes a problem with the grep command  
 
    
.
.
.
94) Patch 00152.00 - Memory leak when creating and destroying widgets       
    95) Patch 00174.00 - Fix for memory leaks in Xlib                           
    96) Patch 00176.00 - Memory leaks occur when creating widgets               
    97) Patch 00180.00 - Fixes memory leak in libXm                             
    98) Patch 00182.00 - libXm memory leak when creating widgets                
 
Or you may choose one of the following options:
 
    99) ALL of the above 
   100) CANCEL selections and redisplay menus
   101) EXIT without installing any patches 
 
Enter your choices or press RETURN to redisplay menus.
 
Choices (for example, 1 2 4-6): 99
 
You are installing the following optional patches:

The program lists the patches you have selected, asks you to confirm the selection, and runs the preinstallation check if you answer yes:

Is this correct? (y/n): y
 
Checking patch prerequisites and patch file applicability...
  (depending upon the number of patches you select, this may take awhile)
 
 
   *** You have selected 98 patches ***
 
 Checking system space needed for patch installation and backup...
 
 
   **************************************************************
 
    Pre-Installation Check COMPLETED with the following results: 
 
    98 patches passed Pre-Installation Check
 
    0 patches failed Pre-Installation Check
 
 
   **************************************************************
 
 
 
 
Press RETURN to continue...

The program lists any patches that fail the prerequisite and applicability checks, and asks how you want to proceed. You have the following choices:
```
Select the action you'd like to take:
 
1)  proceed with the patches that passed the check
2)  select patches again
3)  go back to the previous menu
 
 
```
If the patches are prevented from being installed because of missing or unknown system files, set the system patch baseline, as described in Section 4.7. If patches are prevented from being installed because dependent patches were not selected, choose the select patches again item and add the required patches that are missing.
Otherwise, proceed to the installation phase, as described in Section 4.8.

4.7 Setting the System Patch Baseline

If your system was customized as a result of the manual installation of any system files, you will need to set the patch baseline for your system. If you do not need to set the patch baseline for your system, proceed to Section 4.8.

Note

You will need to be familiar with the concepts of baselining in Section 2.6 before preforming the steps in this section.

You can set the patch baseline in multiuser mode, thereby minimizing system down time.

The following steps show you how to set a patch baseline.

Log in as root.

Run dupatch and enter 5 in response to the Enter your choice prompt of the Main Menu:

Tru64 UNIX Patch Utility (Rev. 29-01)
         ==========================
             - This dupatch session is logged in /var/adm/patch/log/session.log
 
             Main Menu:
             ---------
 
             1)  Patch Installation
             2)  Patch Deletion
 
             3)  Patch Documentation
             4)  Patch Tracking
 
             5)  Patch Baseline Analysis/Adjustment
 
             h)  Help on Command Line Interface
 
             q)  Quit
 
         Enter your choice: 5

A summary of the patch baselining phases will be displayed on the screen.

Answer y or n when asked if you want to proceed with setting the patch baseline (you must provide an answer; there is no default answer):
```
Do you want to proceed with the analysis and adjustment? [y/n]: y
 
 
```
If you answer yes, dupatch asks you to enter the location of the patch distribution as follows:
```
Enter path to the top of the patch distribution,
or enter "q" to get back to the menu :  /mnt/PatchKit/kit2/patch_kit
```

The summary of the patch baselining phases provides the following information:

Baselining Phase 1 evaluates your system relative to the patch kit.

Baselining Phase 2 reports information for patches whose installation is blocked by system files that were installed by layered products. You cannot enable dupatch to install patches that replace system files installed by layered products. You must contact your layered product customer services or Compaq Services if you have purchased Business Critical Services.

Baselining Phase 3 reports on patches that match existing files on your system, but are not marked as installed by the system inventory. You can tell dupatch to mark these patches as installed. This involves copying valid setld database information to your system. If exact matches are found you will be asked the following question:
```
Do you want to mark these patches as installed ? [y/n]
```
You must provide an answer; there is no default answer.

Baselining Phase 4 reports information about any unknown or missing system files. This information is provided to assist you in understanding the state of files that may prevent patch installation.
Consider this information carefully when making decisions to override patch-installation checks for patches noted in Phase 5.

Phase 5 reports patches that do not pass installation applicability tests due to the current state of your system. The installation of these patches is prevented by missing or unknown system files.
The dupatch utility reports the known information about the files contained in each patch and asks if you want to enable the installation:
```
Do you want to enable the installation of any of these patches? [y/n]:
 
```
You must provide an answer; there is no default answer.
Answer n, until you know the origin of the files that are preventing the patch installation. The changed system files that are preventing the official patch installation may be part of a manually installed customer-specific patch or an intentionally customized utility or file.
If, for example, the file that is preventing the installation of an official patch is one of many files that are part of a customer-specific patch, you must determine how to proceed. For more information, see Section 2.6.4.1 and Section 2.6.5.
If you answer y to this question, you can selectively enable dupatch to install patches that are prevented from being installed by missing or unknown files.
The dupatch utility will present the list of patches so you can optionally enable installation. It then asks you how to proceed.
If you select patches for installation, dupatch asks you to confirm your selections and then enables installation of the selected patches. Perform the patch installation as described in Section 4.8.

Caution

Do not enable dupatch to install patches over missing or unknown system files for which you do not know the origin. To do so might leave your operating system or TruCluster software software environments in an inconsistent or nonoperational state.

4.8 Installing and Enabling Patches

Patch installation is performed through dupatch. The -l of the setld command is disabled for patch subsets.

Before beginning the installation, make sure that you have completed all of the preliminary steps:

Make sure you have met the installation prerequisites described in Section 4.2.

Make sure you made the patch distribution available to your system, as described in Section 4.3.

Make sure you loaded any new patch tools, as described in Section 4.4.

Make sure that you performed the patch preinstallation check, as described in Section 4.6.

If needed, make sure that system patch baseline has been set, as described in Section 4.7.

The following sections provide step-by-step instructions for installing and enabling patches.

Note

If you are installing patches on a cluster, see Chapter 5 before you begin the patching process.

4.8.1 Choosing Single-User or Multiuser Mode

You can install patches from either single-user or multiuser modes. See Section 3.1 for information about selecting one of these modes. Section 4.8.1.1 describes the process from single-user mode and Section 4.8.1.2 describes the process from multiuser mode. Section 4.8.2 describes the remaining steps, which are common to installations from single-user and multiuser modes.

4.8.1.1 Installing Patches from Single-User Mode

The following steps describe the steps you take and the type of output you will see when you install patches from single-user mode.

Halt the system. For example:

# /usr/sbin/shutdown -h +5 "Applying 5.0A and TCR Patches"

Boot to single-user mode from the console prompt. For example:
```
>>>boot -fl s 
```

Mount the file system that contains the /usr and /var directories and run the init s command:
```
# /sbin/init s
 
 
```

Run the bcheckrc command to check and mount all the UFS and AdvFS file systems and the lmf reset command to copy license details for all enabled products from the License Database to the kernel cache:
```
# /sbin/bcheckrc
# /usr/sbin/lmf reset
 
 
```

Issue the update command and activate your swap partition with the swapon command:
```
# /sbin/update
# /sbin/swapon -a
```

If you need access to the network, enter the rcinet command to enable the network:
```
# /usr/sbin/rcinet 
```
Informational messages will appear on the screen.

Run the dupatch utility. (This step assumes that the patch kit is available to your system, as described in Section 4.3, and that the new patch tools have been loaded, as described in Section 4.4). Enter 1 at the Enter your choice prompt to the invoke the patch installation session:

# dupatch
 
     Tru64 UNIX Patch Utility (Rev. 29-01)
     ==========================
             - This dupatch session is logged in /var/adm/patch/log/session.log
 
         Main Menu:
         ---------
 
         1)  Patch Installation
         2)  Patch Deletion
 
         3)  Patch Documentation
         4)  Patch Tracking
 
         5)  Patch Baseline Analysis/Adjustment
 
         h)  Help on Command Line Interface
 
         q)  Quit
 
     Enter your choice: 1

When the patch installation menu is displayed. Enter 2, at the Enter your choice prompt:

     Tru64 UNIX Patch Utility (Rev. 29-01)
     ==========================
             - This dupatch session is logged in /var/adm/patch/log/session.log
 
         Patch Installation Menu:
         -----------------------
 
         1)  Pre-Installation Check ONLY
         2)  Check & Install patches in Single-User Mode
 
         b)  Back to Main Menu
         q)  Quit
 
         Enter your choice: 2

4.8.1.2 Installing Patches from Multiuser Mode

The following list describes the steps you take and the type of output you will see when you install patches from multiuser mode.

Run the dupatch utility. (This step assumes that the patch kit is available to your system, as described in Section 4.3, and that the new patch tools have been loaded, as described in Section 4.4). Enter 1 at the Enter your choice prompt to the invoke the patch installation session:

# dupatch
 
     Tru64 UNIX Patch Utility (Rev. 29-01)
     ==========================
             - This dupatch session is logged in /var/adm/patch/log/session.log
 
         Main Menu:
         ---------
 
         1)  Patch Installation
         2)  Patch Deletion
 
         3)  Patch Documentation
         4)  Patch Tracking
 
         5)  Patch Baseline Analysis/Adjustment
 
         h)  Help on Command Line Interface
 
         q)  Quit
 
     Enter your choice: 1

When the patch installation menu is displayed. Enter 3, at the Enter your choice prompt:

     Tru64 UNIX Patch Utility (Rev. 29-01)
 ==========================
	 - This dupatch session is logged in //var/adm/patch/log/session.log
 
     Patch Installation Menu:
     -----------------------
 
    1)  Pre-Installation Check ONLY
    2)  Check & Install in single-user mode w/ network services
    3)  Check and Install in Multi-User mode
 
    b)  Back to Main Menu
    q)  Quit
 
Enter your choice: 3
 
		                    *** Installation Warning ***
 
You have chosen to install patches onto this system while it is running in
Multi-User mode. Some patches may directly affect core operating system
operations. To insure the proper operation  of all applications, it is strongly
suggested that you install these patches while the system is in
Single-User mode. If this cannot be done, install these patches when the system
is as lightly loaded as possible (i.e. not running production environments, no users
logged on, etc.).
 
Do you wish to continue? (y/n) [y]:

4.8.2 Common Installation Steps

The following steps provide instructions for continuing the installation of Tru64 UNIX and TruCluster software patches after you have selected either single-user or multiuser mode.

You have the option to make patches reversible so you can return the system to its state prior to the installation of a patch. Enter y or press Return to make the patches reversible. For example:
```
Do you want the patches to be reversible? [y]:
```
By default, backup copies of the installed patches are saved in /var/adm/patch/backup. If you have limited space in /var, you may want to make the backup directory the mount point for a separate disk partition, an NFS mounted directory, or a symbolic link to another file system.
If you answer no to this question, the existing system files will not be saved and the installed patches will not be reversible. Compaq recommends that you install patches so they are reversible.

The program describes your backup setup and asks you if you want to proceed:

Do you want to proceed with the installation with this setup? [y]:

You are asked to record your name as the person installing the patches and to add any comments you would like stored for future reference. For example:
```
Your name: Joe
```
Enter any notes about this operation that you would like stored for future reference. To end your input, enter a period (.) and press Return.
```
: Installing Patch Kit 3
: . [Return]
```

The program lists the patches available for installation on your system. This list may be different from system to system because dupatch does not display available patches that are already installed on your system. You can install all patches (as recommended by Compaq) or selectively choose patches for installation. You can also cancel selections and redisplay menus, or exit without installing any patches. The following is an example of the dupatch output:
```
Enter your choices or press RETURN to display the next screen.
 
Choices (for example, 1 2 4-6) :
     
.
.
.
130) Patch 0381.00 - Motif Toolkit Correction
     131) Patch 0384.00 - Various X11 Server Corrections
 
Or you may choose one of the following options:
 
     134) ALL of the above
     133) CANCEL selections and redisplay menus
     134) EXIT without installing any patches
 
 
```
Selecting CANCEL cancels your patch selections and returns to the patch list and selection menus so you can reselect patches for installation.
Selecting EXIT returns you to the dupatch installation menu.

Note

When installing customer-specific patches, you do not have the option of selecting individual patches; you must install them all. You can, however, remove individual CSPs after the installation process is completed and the system has been rebooted.

The preinstallation check verifies that the patches will install. If the preinstallation check is successful, dupatch proceeds with the installation. If the preinstallation check fails, dupatch lists the specific patches that fail and asks how you want to proceed:
```
Select the action you'd like to take:
 
1)  proceed with the patches that passed the check
2)  select patches again 
3)  go back to the previous menu
```
If you choose to proceed with patches that passed the preinstallation check, dupatch will start installing those patches and provide informational messages on the screen. The entire dupatch session is logged to ensure you can view any messages that may scroll off the screen.
If patch installation is blocked due to missing or unknown system files, refer to Section 4.7.

Review the dupatch session log, /var/adm/patch/log/session.log, to ensure that the installation was successful. Note any special patch instructions, informational messages, and error messages. (See Section 2.2 for information about dupatch logs.)

Assuming the patch installation was successful, rebuild the kernel (vmunix), save the existing kernel, move the new kernel into place, and reboot the system. For more information, see the Tru64 UNIX System Administration manual.
The following steps show the typical process:
1. Configure a new vmunix. For example:
```
# doconfig -c HOSTNAME
```
2. Save the existing vmunix. For example:
```
# cp /vmunix /usr/vmunix.prekit11-<yyyymmdd>
```
3. Install the newly built kernel (vmunix). For example:
```
# mv /usr/sys/HOSTNAME/vmunix  /vmunix
```
4. Reboot the system. For example:
```
# /usr/sbin/shutdown -r +5 \
"Reboot with newly installed patches"
```

4.9 Rebuilding the Kernel

The dupatch utility determines whether the installation or removal of patches requires that the kernel be rebuilt and the system rebooted. This action is then performed automatically or manually, depending upon the method you used to install the patches:

When using the command line, the kernel is built automatically with the doconfig utility, using the -a option. It also uses the -c option of the -cfgfile command line option if that command was used.

When using the menu-based interface, the kernel build occurs as if doconfig was entered from the command line. The dupatch utility asks if your system has a custom configuration file and if you want to change it.

4.10 Rebooting the System

The action that dupatch takes to reboot your system depends upon whether you used the command-line or menu-based interface or performed the action in single-user or multiuser mode.

4.10.1 In Single-User Mode

When performing a patch installation or removal in single-user mode from the command line, the system automatically reboots after the command line operation is completed.

When performing a patch installation or removal in single-user mode using the menu-based interface, dupatch asks if you want to reboot the system after the patch installation or removal is completed:

If you answer yes, the system reboots immediately.

If you answer no, dupatch returns to the appropriate menu -- either installation or removal, depending on the operation.

4.10.2 In Multiuser Mode

When installing patches in multiuser mode from the command line, you are given a message informing you that a reboot is necessary to complete the patch installation. However, the system does not reboot itself.

When installing patches in multiuser mode using the menu-based interface, dupatch gives you three options if a reboot is necessary:

Reboot now

Schedule a reboot for a later time

Do not reboot

4.11 Removing Patches

To remove patches from your system , use the Patch Deletion option of the dupatch Main Menu. The system must be in single-user mode to remove patches. Note that the -d option to the setld command is disabled for patch subsets.

The following steps show how to remove patches:

Caution

The Patch Deletion menu lists every setld-based patch on your system, regardless of which patch kit installed them. Therefore, if you select the ALL of the above menu item, it will remove all setld-based patches from your system.
For example, if you chose the ALL of the above menu item when installing Patch Kit-0003 and then decide to remove those patches, you will have to specify the patch ID of all Patch Kit-0003 patches in the Delete Patch menu. If, instead, you select the ALL of the above menu item, then all setld-based patches that are installed on your system are removed, not only those from Patch Kit-0003.

Halt the system and bring it up in single-user mode, as described in Section 4.8.1.1.

Run dupatch and select 2 for patch removal:

# dupatch
 
Tru64 UNIX Patch Utility
==========================
(This dupatch session is logged in /var/adm/patch/log/session.log) 
 
Main Menu:
----------
 
1) Patch Installation 
2) Patch Deletion
 
3) Patch Documentation 
4) Patch Tracking 
 
5) Patch Baseline Analysis/Adjustment 
 
h) Help on Command Line Interface
 
q) Quit  
 
Enter your choice: 2

You are asked to record your name as the person removing the patches and to add any comments you would like stored for future reference. For example:
```
Your name: Mike
```
Enter any notes about this operation that you would like stored for future reference. To end your input, enter a period (.) and press Return.
```
: Removing patches 6.00, 12.00, and 22.00 until the
: firmware can be updated to the proper revision.
         : . [Return]
```

Select and verify the patches to be removed through the patch selection menus. Once the patch selection is done, dupatch removes the selected patches and provides informational messages on the screen. The dupatch session is logged to /var/adm/patch/log/session.log. (See Section 2.2 for information about dupatch logs.)

Note

When removing patches after incremental installations, you may see Special Instructions from previously installed patches that have since been superseded. You should ignore these instructions and instead follow any Special Instructions relating to the most current patch.

Review the session log to ensure the removal was successful. Note any special patch instructions, informational messages, and error messages.

If there are no error messages, follow the instructions for disabling the patches that are listed in the session log. Depending on the removed patches, you may need to rebuild the kernel or reboot the system.