To avoid contention among disk accesses, a user LOB RDAREA should not be placed on the same disk as any other RDAREA.
If you have partitioned a table by row, place the RDAREAs storing the row-partitioned table on separate disks. The following figure shows an example of user LOB RDAREA placement.
Figure 8-8 Example of user LOB RDAREA placement (HiRDB/Single Server)