Performing a mksysb migration with NIM installation

You can perform a mksysb migration with a NIM installation of AIX® Version 7.2.


  • All requisite hardware, including any external devices (such as DVD-ROM drives), must be physically connected. For more information about connecting external devices, see the hardware documentation that accompanied your system.
  • Before you begin the installation, other users who have access to your system must be logged off.
  • Verify that your applications run on AIX Version 7.2. Also, verify that your applications are binary-compatible with AIX Version 7.2. If your system is an application server, verify that there are no licensing issues. Refer to your application documentation or provider to verify on which levels of AIX Version 7.2 your applications are supported and licensed.
  • Verify that your hardware microcode is up-to-date.
  • There must be adequate disk space and memory available. AIX Version 7.2 requires minimum 4 GB of memory and 20 GB of physical disk space. For additional release information, see the AIX Release Notes.
  • Make a backup copy of your system software and data. For instructions on how to create a system backup, refer to Creating system backups. This backup is used during the mksysb migration installation to restore your system files prior to migration.
  • If the source system is available, run the pre_migration script on it. Ignore any messages that pertain to the hardware configuration of the source system because the migration takes place on the target system. Correct any other problems as recommended by the script.

Step 1. Prepare your system for installation

To prepare your system, verify that the following conditions are met:
  • The target system must be a defined client to the NIM master.
  • The required customized file described in the prerequisites is a NIM resource or supplied using the supplemental diskette method.
To instruct the NIM master to start an installation of the client run the following command:
# nim -o bos_inst -a source=rte -a spot=spot name -a lpp_source=lpp source name
 -a bosinst_data=bosinst_data resource name -a mksysb=mksysb name client_name 

The SPOT file and lpp_source file must be at the AIX Version 7.2 level.

Alternatively, the mksysb can be allocated to the client first using a separate alloc operation. Then use command line or smitty nim to perform a bos_inst operation on the client. If the mksysb is allocated to the client prior to the bos_inst operation, the specification of the mksysb is not required.

Step 2. Boot from your installation media

The following steps migrate your current version of the operating system to AIX Version 7.2. If you are using an ASCII console that was not defined in your previous system, you must define the console. For more information about defining ASCII consoles, see Step 3. Setting up an ASCII terminal.

  1. After the network boot image is transferred, the system begins booting using the network resources.
  2. The mksysb migration installation proceeds as an unattended installation (non-prompted).

The BOS menus do not currently support mksysb migration, so they cannot be loaded. In a traditional migration, if there are errors that can be fixed by prompting the user for information through the menus, the BOS menus are loaded. If such errors or problems are encountered during mksysb migration, the installation asserts and an error stating that the migration cannot continue displays. Depending on the error that caused the assertion, information specific to the error might be displayed. If the installation asserts, the LED shows "088".

Step 3. Finish the BOS migration

After the installation process begins, the Installing Base Operating System screen displays.

As the installation progresses, the numbers in the percentage complete field and the elapsed time field increment to indicate the installation status. After the mksysb is restored, the base run-time environment is installed, status information about other software that is being installed displays. After the BOS installation is complete, the system automatically reboots.

After the system has restarted, you are prompted to configure your installation of the BOS. For more information on configuring the BOS, see Configuring AIX.

If there is not enough space to migrate all of the usually migrated software, a collection of software called a migration bundle is available when you install additional software later. You must create additional disk space on the machine where you want to install the migration bundle, and then you can run smit update_all to complete the installation where the migration bundle is installed.

If you are not doing the installation from a graphics console, a Graphics_Startup bundle is created. For more information on this, see Optional products and service updates. For information on how to remove software from the system to release disk space, see Maintaining optional software products and service updates.

If the pre-migration script ran on the source system, run the post-migration script and verify the output files.