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Installation Guide

Chapter 7. Installing System Backups

This chapter describes how to install the Base Operating System (BOS) from a backup image of a previously installed system. You can use a system backup to restore a corrupted operating system. But installing a system from a backup can also reduce, or even eliminate, repetitive installation and configuration tasks. For example, you can use a backup to transfer optional software installed on the source system (the machine from which you created the backup copy), in addition to the basic operating system. Also, the backup image can transfer many user configuration settings to the target system (a different machine on which you are installing the system backup).

The procedure you use to install from a system backup depends on whether you are installing on the source or target system and which interface you want to use:

You can install a system from a backup image that is stored on tape or CD, or in a file. If you want to install a backup stored in a directory on your network installation server, refer to AIX 5L Version 5.1 Network Installation Management Guide and Reference.

The procedures to install from backup operate either in prompted or nonprompted mode, depending on conditions set in the /bosinst.data file and on compatibility between the backup image and the installed machine. See Chapter 8, Customized BOS Installations for information on how to modify the bosinst.data file to preset installation parameters when you create a system backup.

When installing the backup image, the system checks whether the target system has enough disk space to create all the logical volumes stored on the backup. If there is enough space, the entire backup is recovered. Otherwise, the installation halts and the system prompts you to choose additional destination hard disks.

File systems are created on the target system at the same size as they were on the source system, unless the backup image was created with SHRINK set to yes in the image.data file or you set it to yes in the BOS Install menus. An exception is the /tmp directory, which can be increased to allocate enough space for the bosboot command. For information about setting variables, refer to the image.data file in AIX 5L Version 5.1 Files Reference.

After installing the backup image, the installation program reconfigures the Object Data Manager (ODM) on the target system. If the target system does not have exactly the same hardware configuration as the source system, the program might modify device attributes in the following target system files:

The installation program automatically installs only the device support required for the hardware configuration of the source system. A target system that requires different device support or a different kernel can be installed with the source system's mksysb image on tape or on a personal backup CD or DVD, by booting from a product CD and then using the mksysb media to install the system. Any additional device support required on the target system is automatically installed after the mksysb image is restored. For further information, refer to Cloning a System Backup .

Additional devices needed for the target system can also be installed on the source system before making the mksysb image. To install additional device support on the source system, use the Web-based System Manager or SMIT. In Web-based System Manager, expand Devices then choose Overview and Tasks and select the Install additional device drivers or software wizard. In SMIT, use the Install Software menu option (smit install_all fast path).

Cloning a System Backup

With a mksysb image, you can clone one system image onto multiple target systems. The target systems might not contain the same hardware devices or adapters, require the same kernel (uniprocessor or microprocessor), or be the same hardware platform (rs6k, rspc, or chrp) as the source system. If you are installing a mksysb on a target system, use the procedure Cloning Your System.

To create a backup CD or DVD that can be installed on any POWER-based machine running the operating system (a generic backup CD). refer to Creating System Backups on CD-ROM.

Cloning Your System

Use this procedure to install a mksysb image on a target system it was not created on. Be sure to boot from the product media appropriate for your system and at the same maintenance level of BOS as the installed source system that the mksysb was made on. For example, use BOS AIX 5.1 media with a mksysb from a BOS AIX 5.1 system. Use this procedure when installing a backup tape to a different system, or if installing a personal backup CD to a different system. It is not necessary whenyou are installing with generic backup CDs.

After booting from the system backup media, complete the following steps when the Welcome to the Base Operating System Installation and Maintenance screen displays.

  1. Select the Start Maintenance Mode for System Recovery option.
  2. Select the Install from a System Backup option.
  3. Select the drive containing the backup tape or CD, insert the media for that device, and press Enter to continue.

    The system reads the media and begins the installation.

    You are then prompted for the BOS installation language, and the Welcome screen displays. Continue with the Prompted Installation, as cloning is not supported in nonprompted installations.

  4. If you are cloning from the product CD to restore a backup tape, do not remove the CD from the CD-ROM drive. If you are restoring from a backup CD, you might be prompted to remove the CD. You are then prompted again for the BOS install language, and the Welcome screen displays. Continue with the Prompted Installation process.


    1. Booting from tape is not supported on some rspc platform systems. When a backup tape has been created on one of these systems, the mksysb command displays a message indicating that the system does not support tape boot. To determine what your platform system is, enter the following command:

      bootinfo -p
    2. If you are cloning from a product tape to restore a backup tape, or if you are cloning from a product CD to restore from a backup CD, create a diskette that contains a ./bosinst.data file with SWITCH_TO_PRODUCT_TAPE=yes in the control_flow stanza if this was not set when creating the mksysb image.

      If SWITCH_TO_PRODUCT_TAPE is set to yes, the system prompts you to remove the mksysb media and insert the product media after the mksysb image has been restored.

After the mksysb installation completes, the installation program automatically installs additional devices and the kernel (uniprocessor or microprocessor) on your system using the original product media you booted from. Information is saved in BOS installation log files. To view BOS installation log files, type cd /var/adm/ras and view the devinst.log file in this directory.

If the source system does not have the correct passwords and network information, you can make modifications on the target system now. Also, some products (such as graPHIGS) ship device-specific files. If your graphics adapter is different on the target system, verify that the device-specific filesets for graphics-related LPPs are installed.

Attention: If the system you have cloned is using OpenGL or graPHIGS, there might be some device filesets from these LPPs that must be installed after a clone. OpenGL and graPHIGS have graphics adapter-specific filesets, so if you cloned onto a system with a different graphics adapter, you must create a bundle as follows:

echo OpenGL.OpenGL_X.dev > /usr/sys/inst.data/user_bundles/graphic_dev.bnd
echo PEX_PHIGS.dev >> /usr/sys/inst.data/user_bundles/graphic_dev.bnd

Next, type smitty install_bundle on the command line to install this bundle. If any new filesets are installed, you can reboot your system before using OpenGL and graPHIGS. Otherwise, you might experience performance problems with these applications.

The above procedure is required because the OpenGL and graPHIGS LPPs are on a separate media, and therefore the normal cloning procedure cannot automatically install any missing device filesets.

The Network Installation Management (NIM) mksysb installation also supports cloning. If you are using NIM and you have OpenGL and graPHIGS in your lpp_source, you can create a separate bundle as described above and allocate it when you install the mksysb image. The device filesets are installed automatically.

Installing a System Backup on the Source Machine

You can use Web-based System Manager or SMIT to retore an operating system onto the same machine from which you created the backup. For either interface, the following conditions must be met before beginning the procedure:

CD/DVD BOS CDs, created in one of the following ways:
  • Using the Web-based System Manager Backup and Restore application. Select System backup to writable CD.
  • Using the SMIT Back Up This System to CD menu.
  • From the command line, using the mkcd command.
Tape BOS tapes, created in one of the following ways:
  • Using the Web-based System Manager Backup and Restore application. Select Back up the system.
  • Using the SMIT Back Up the System to Tape/File menu.
  • From the command line, using the mksysb -i Target command.
Network The path to your backup image file. Refer to AIX Version 4.3 Network Installation Management Guide and Reference for information about installing a backup across a network.

Note: Before you begin, select the tape or CD/DVD-ROM drive as the primary boot device. For additional information, refer to the section in your hardware documentation that deals with system management services.

To use Web-based System Manager:

  1. Start the Web-based System Manager by typing wsm on the command line as root user.
  2. Expand Software in the Navigation Area, select Overview and Tasks, then select Reinstall Operating System.
  3. Choose the installation device:
  4. Choose Install a system backup image (mksysb) as the installation type:
  5. Follow the wizard prompts to complete the procedure.

To use SMIT:

  1. Verify that your system is shut down. If your machine is currently running, you must power it off now by following these steps:
    1. Log in as the root user.
    2. Enter the following command:

      shutdown -F
    3. If your system does not automatically power off, place the power switch in the Off (0) position.
  2. Turn the system key (if present) to the Service position.

  3. Turn on all attached external devices. These include:

    Turning on the external devices first is necessary so that the system unit can identify them during the startup (boot) process.

    Attention: You must not turn on the system unit until Step 6.
  4. Load the installation media into the tape or CD/DVD-ROM drive.

    You might find that on certain tape drive units, the tape drive door does not open while the system is turned off. If you have this problem, use the following procedure:

    1. Turn on the system unit.
    2. Insert the boot installation tape (insert Volume 1 if you received more than one volume).
    3. Turn off the system unit and wait for 30 seconds.
  5. If you are not using an ASCII terminal, skip to Step 6. If you are using an ASCII terminal, set the options using the criteria listed below to set the communications, keyboard, and display options.

    Note: If your terminal is an IBM 3151, 3161, or 3164, press the Ctrl+Setup keys to display the Setup Menu and follow the onscreen instructions to set these options. If you are using some other ASCII terminal, refer to the appropriate documents for information about how to set these options. Some terminals have different option names and settings than those listed here.

    Communication Options
    Option Setting
    Line Speed (baud rate) 9600
    Word Length (bits per character) 8
    Parity no (none)
    Number of Stop Bits 1
    Interface RS-232C (or RS-422A)
    Line Control IPRTS


    Keyboard and Display Options
    Option Setting
    Screen normal
    Row and Column 24x80
    Scroll jump
    Auto LF (line feed) off
    Line Wrap on
    Forcing Insert line (or both)
    Tab field
    Operating Mode echo
    Turnaround Character CR
    Enter return
    Return new line
    New Line CR
    Send page
    Insert Character space

  6. Turn the system unit power switch from Off (0) to On (|). The system begins booting from the backup media. If your system is booting from tape, it is normal for the tape to move back and forth. After several minutes, the three-digit LED should display c31.

    Note: You can boot from production media (tape or CD) if your backup media fails to boot. The initial Welcome screen includes an option to enter a maintenance mode in which you can continue the installation from your backup media. Refer to Troubleshooting an Installation from a System Backup for more information.

    If you have more than one console, each terminal and directly attached display device (or console) might display a screen that directs you to press a key to identify your system console. A different key is specified for each terminal displaying this screen. If this screen is displayed, then press the specified key only on the device to be used as the system console. (The system console is the keyboard and display device used for installation and system administration.) Press a key on only one console.

    Note: If the bosinst.data file lists a valid display device for the CONSOLE variable, you do not manually choose a system console. Read Chapter 8, Customized BOS Installations for more information about the bosinst.data file.
  7. The type of installation that begins is determined by the settings of the PROMPT field in the control_flow stanza of the bosinst.data file. Use the following criteria to determine the type of installation you will be using:
    PROMPT = no Nonprompted Installation. This installation method is used if the backup image is configured to install automatically, without having to respond to the installation program. Go to step 8.
    PROMPT = yes Prompted Installation. This installation method is used if you need to use menu prompts to install the backup image. Also, use this installation method if a nonprompted installation halts and the Welcome to Base Operating System Installation and Maintenance screen displays. Go to step 9.
  8. A successful nonprompted installation requires no further instructions because the installation is automatic.

    Note: If the backup image holds source system configuration information that is incompatible with the target system, the nonprompted installation stops and a prompted installation begins.

    The Installing Base Operating System screen displays before the installation starts. The nonprompted installation pauses for approximately five seconds before beginning. During this short pause, if you decide to interrupt the automatic installation and start a prompted session, you only need to type 000 (three zeros) at the terminal and continue the installation in prompted mode.

    The system reboots automatically if the system key (if present) is in the Normal position. Otherwise, you must manually reboot the system when directed by turning the system key to Normal and pressing the Enter key.

    To complete your installation of the backup image, review the information in the section titled Where Do I Go Next?.

  9. The Welcome to the Base Operating System Installation and Maintenance screen displays.

    Note: You can view Help information at each screen of this installation process by typing 88.

    Choose the Change/Show Installation Settings and Install option.

  10. The System Backup Installation and Settings displays. This screen shows current settings for the system. An ellipsis follows the disk listed in the first line if there is more than one disk selected.

  11. Either accept the settings or change them. For more information on using map files, see Chapter 6, Creating System Backups.

    To accept the settings and begin the installation, skip to step 16.

    To change the settings, continue with step 12.

  12. Type 1 in the System Backup Installation and Settings screen to specify disks where you want to install the backup image. The Change Disk(s) Where You Want to Install screen displays.

    This screen lists all available disks on which you can install the system backup image. Three greater-than signs (>>>) mark each selected disk.

    Type the number and press Enter for each disk you choose. Type the number of a selected disk to deselect it. You can select more than one disk.

    Note: You can also specify a supplemental disk by typing 66 and pressing the Enter key for the Disks not known to Base Operating System Installation option. This option opens a new menu that prompts for a device support media for the supplemental disk. BOS installation configures the system for the disk and then returns to the Change Disk(s) Where You Want to Install screen.
  13. After you have finished selecting disks, press the Enter key.

    The screen that displays after you press the Enter key is dependent on the availability of map files for all of the selected disks. The criteria for this is as follows:

    To preserve the placement of files during a future restoration of the backup, you can create map files before backing up a system. Map files, stored in the /tmp/vgdata/rootvg directory, match the physical partitions on a drive to its logical partitions. Create map files either with the SMIT Backup the System menu, using Web-based System Manager, or using the -m option when you run the mksysb command.

    For more information about map files, see Using Map Files for Precise Allocation in AIX 5L Version 5.1 System Management Concepts: Operating System and Devices.

  14. Type either 1 or 2 in the Change Use Maps Status screen to specify whether the installation program is to use maps.

    When you complete this choice, BOS installation returns to the System Backup Installation and Settings screen.

  15. Decide whether BOS installation is to shrink file systems on the disks where you install the system. When you choose this option, the logical volumes and file systems within a volume group are re-created to the minimum size required to contain the data. This reduces wasted free space in a file system.

    File systems on your backup image might be larger than required for the installed files. Press the 2 key to toggle the Shrink File Systems option between Yes and No in the System Backup Installation and Settings screen. The default setting is No.

    Note: Shrinking the file system disables the use of maps.
  16. Type 0 to accept the settings in the System Backup Installation and Settings screen.

    The Installing Base Operating System screen displays the rate of completion and duration.

    The Please turn the system key to the NORMAL Position message displays on this screen if the key is not already in the Normal position. Because the installation continues regardless of the key position, you can turn the key at any time while the screen is showing.

    An untitled screen temporarily replaces the Installing Base Operating System screen if you specified a supplemental disk in step 12 12. When this screen displays, it prompts you to place the device-support media in the drive and press the Enter key. BOS installation reconfigures the supplemental disk, then returns to the Installing Base Operating System screen.

    The system reboots automatically when the installation completes.

    The reboot is automatic if the system key (if present) is in the Normal position. Otherwise, a new screen directs you, at the end of the installation, to turn the key to Normal and press Enter. The system reboots, in this case, when you press the Enter key.

Where Do I Go Next?

In new installations on graphical systems, a post-installation program, Configuration Assistant, starts automatically when BOS installation reboots the system. For ASCII systems, the post-installation configuration program is Installation Assistant. Whether this configuration program starts following your backup installation depends on settings in your backup image:

Go to Chapter 3, Configuring the Operating System to configure the installed machine with optional software, network communications, user accounts, and other settings.

If the Configuration Assistant (or Installation Assistant for ASCII) does not start automatically, and you do not want to configure the machine, the installation from backup is complete.

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