Running the AIX pre_migration command

Learn when you should run and how to run the AIX® pre_migration command.

Before you migrate AIX, ensure that your server does not have existing installation issues.

If you are migrating to AIX 5.3 or later, you can run the pre_migration command on the CD that runs a set of tests and verifications on your server before you start the migration process. All output from the pre_migration command is saved in the /home/pre_migration.date directory. To run the pre_migration command, complete the following steps:

Mount the AIX 5.3 CD using the following command:
```
# mount -v cdrfs -o ro /dev/cd0 /mnt
```
Copy the script to your server. The script is located in the /mnt/usr/lpp/bos/pre_migration directory. Run the following command:
```
 # cp /mnt/usr/lpp/bos/pre_migration /tmp/pre_migration 
```
Run the script using the following command:
```
# /tmp/pre_migration
```

The script performs the following checks:

Placement and size of boot logical volume
Requirements for disk space
Verification of current system installation

If any problems are found, they are logged and reported to you. The premigration script does not make any changes on the server. The script verifies the current environment and checks for specific circumstances that might cause problems during a migration.

Run the premigration script before starting any migration, including alternate disk migration. Although all of the checks are also done before migration, it is easier to correct problems on a running server.