Before you migrate data, you need to determine whether to perform a one-step migration or a two-step migration.
One-step migration All the data is extracted for all selected mailboxes and then immediately imported. The disk for the temporary directory must be large enough to store the migrated data. This is the recommended option.
Two-step migration All selected information is extracted to the migration files. You then edit the migration files as needed and import them. This is the only way to change the default directory name.
Note The source extractor creates a temporary binary initialization file (BIF) based on the existing file. When migration is complete, the source extractor removes this temporary file.