Release 10.1A: OpenEdge Getting Started:
Database Essentials

Guidelines for choosing storage area locations

When you choose the locations for your database storage areas, consider the following:

Protect against disk failures by creating the after-image storage area on a separate physical disk from the disks that store the database control and primary recovery areas.
Improve performance by creating the primary recovery area on a separate disk from the disk that stores the database control area and its extents.
If using two-phase commit, create the transaction log area in the same directory as the database control area to simplify management.