You can improve SU performance by storing central databases on disk in the following manner:

• Store your central databases on disk packs that have little activity besides SU.
• Store them on volumes not used for paging or swapping and do not store them on a system volume.
• Store each database on a separate volume if possible. If this is not possible, try to distribute the databases across as many volumes as possible.
• Do not drive the volumes higher than their normal I/O rates. For stated device I/O rates, see the appropriate IBM publication.