Veritas Volume Manager (VxVM) offers a variety of layouts that enables you to configure your database to meet performance and availability requirements. The proper selection of volume layouts provides optimal performance for the database workload.

Disk I/O is one of the most important determining factors of database performance. Having a balanced I/O load usually means optimal performance. Designing a disk layout for the database objects to achieve balanced I/O is a crucial step in configuring a database. When deciding where to place tablespaces, it is often difficult to anticipate future usage patterns. VxVM provides flexibility in configuring storage for the initial database set up and for continual database performance improvement as needs change. VxVM can split volumes across multiple drives to provide a finer level of granularity in data placement. By using striped volumes, I/O can be balanced across multiple disk drives. For most databases, ensuring that different containers or tablespaces, depending on database, are distributed across the available disks may be sufficient.

Striping also helps sequential table scan performance. When a table is striped across multiple devices, a high transfer bandwidth can be achieved by setting the DB2 parameter DB_FILE_MULTIBLOCK_READ_COUNT to a multiple of full stripe size divided by DB_BLOCK_SIZE.

Another very important consideration when using the DB2 database, which by default performs striping at the tablespace container level, is setting the DB2_STRIPED_CONTAINERS variable.

If you plan to use the Database FlashSnap feature (point-in-time copy) for your DB2 database and use it on either the same host or for off-host processing or backup, the layout of volumes should meet the FlashSnap requirements.