Running the database premigration checker

Prior to running the database migration, run the premigration checker to expose any issues with the database that might cause errors during the migration. This allows you to correct any issues, ensuring that your database migration completes successfully.

Procedure

Open a command window:
- Open a shell prompt window on the WebSphere Commerce version 7.0 machine, and switch to the WebSphere Application Server user ID (for example, wasuser) by entering the following command:
```
su - wasuser
```
- Start a Qshell session.
- Open a DB2 command window
- Open a command prompt window.
Run the database premigration checker. Navigate to the WC_installdir/bin directory and run the following command:
```
./wcim_ant.sh -tier db -action check -from previous_version -instanceName instance_name
```
```
wcim_ant.bat -tier db -action check -from previous_version -instanceName instance_name
```
Where:

previous_version

Is the current WebSphere Commerce version you are migrating from for example, 561 or 60.
Notes:
1. The migration script will prompt you to enter the database user name, password, database name, and whether the database is on the remote machine and the remote machine name. When you input the remote machine name, you need enter the fully qualified host name or the IP address.
2. The schema name must be same as the user name. If the user name is different than the schema name, you need to transfer the schema to a schema that has same name as user. For information on how to transfer the schema name to another name:
  - Refer to the documentation on the admin_copy_schema command. Depending on the version of DB2 you are using, see one of the following DB2 topics:
    
    DB2 9.5r: ADMIN_COPY_SCHEMA procedure
    
    DB2 9.7: ADMIN_COPY_SCHEMA procedure
  - For instructions on how to change the schema name, consult the database vendor documentation.
  Alternately, you can create a new database user that has the same name as the current schema, then use this user to migrate the database.
Example
```
./wcim_ant.sh -tier db -action check -from 60 -instanceName my_instance_name
>Database type? [ db2 ] (cloudscape,db2,os400,oracle,)
os400
>Remote database? [ false ] (true,false,)
false
>Database name?
my_database_name
>Database user?
my_instance_name
>Database user password?
my_db_password
>Database server port?
50000
>Is this a test run? [ Yes ] (Yes,No,)
Yes
>Is the database backup completed? [ Yes ] (Yes,No,)
Yes
>Is the database restore completed? [ Yes ] (Yes,No,)
Yes
```
Check the following log files for messages or errors:
- WC_installdir/logs/WCIM/wcim.server.yyyy.mm.dd_hh.mm.ss.log
- WC_userdir/logs/WCIM/wcim.server.yyyy.mm.dd_hh.mm.ss.log
- WC_installdir\logs\WCIM\wcim.server.yyyy.mm.dd_hh.mm.ss.log

The database premigration checker checks that you have adequate free disk space to migrate the largest table in your database. If you see a message similar to the following you may have to increase your disk space.


In order to migrate one of the biggest tables table_name in the database,
the database migration script needs at least nn MB in the database log space.
It also needs at least nn MB free disk space in the tablespace.
Otherwise, the database migration may fail.

In order to migrate one of the biggest tables table_name in the database,
the database migration script needs at least nn MB in the database undo segment.
It also needs at least nn MB free disk space in the tablespace.
Otherwise, the database migration may fail.

Complete the actions suggested that are output to the screen or that are contained in the wcim.server.yyyy.mm.dd_hh.mm.ss.log file.
Back up your updated WebSphere Commerce database. Refer to your database documentation for more information.
Run the premigration checker again.