# Configure the File realm

To configure the File realm in the Compatibility security system:

1. If you have not already done so, in the Change Center of the Administration Console, click Lock & Edit (see Use the Change Center).
2. In the left pane, select your domain (for example, mydomain).
3. Select Compatibility Security > File Realm.
4. Enter values in the fields on the File Realm tab.
5. Click Save to save your changes.

   All user and group data for the File realm is stored in the `fileRealm.properties` file. If the `fileRealm.properties` file becomes corrupted or is destroyed, you must reconfigure the security information for WebLogic Server. Compatibility security cannot run without a `fileRealm.properties` file. Even if you write a custom security realm, you still need a `fileRealm.properties` file to boot WebLogic Server. Therefore, Oracle recommends that you take the following steps:

   1. Make a backup copy of the `fileRealm.properties` file and put it in a secure place.
   2. Set the permissions on the `fileRealm.properties` file such that the administrator of the WebLogic Server deployment has write and read privileges and no other users have any privileges.

   Note: Also make a backup copy of the `SerializedSystemIni.dat` file for the File realm.

6. To activate these changes, in the Change Center of the Administration Console, click Activate Changes.
   Not all changes take effect immediately—some require a restart (see Use the Change Center).