Application Use Cases for the HP Serviceguard Storage Management Suite, November 2009

The failover applications can be customized, custom integrated, or a single-instance database. If you

deploy a single-instance Oracle database, HP recommends T2773xx or T2774xx because they

include special features for Oracle database environments.

Users who would like to standardize volume managers on multi-vendor hardware might choose

T2771xx even if they are not looking for any of its unique features.

This bundle is suited for the most basic and cost-effective configurations.

T2773xx: HP Serviceguard Storage Management for Oracle

The HP Serviceguard Storage Management for Oracle (SGSMO) is an integrated product bundle that

includes Serviceguard high availability clustering with Symantec’s VxVM and VxFS, plus special

database accelerators for Oracle that provide the performance of raw mode with the manageability

of a file system. This bundle includes the following individual components:

 HP Serviceguard

 HP Serviceguard Manager

 HP Enterprise Cluster Master Toolkit

 Veritas File System version

 Veritas Volume Manager version

 Veritas Dynamic Multi-Pathing (DMP)

 Veritas Enterprise Administrator

 Storage Checkpoints

 Oracle Disk Manager for Oracle 9i and 10g (ODM)

 Veritas Storage Rollback

SGSMO is the entry-level bundle designed for Oracle single-instance database environments. It

adds database accelerators and other useful functionality for Oracle databases to the contents of

the SGSM bundle.

While this bundle also works for non-Oracle applications (those listed for the SGSM bundle), the

specific functionality added to SGSMO can only be exploited by Oracle databases. An Oracle

single-instance database is the designated application use case for the SGSMO bundle.

The database accelerator, ODM, is the feature that makes this bundle most attractive for

single-instance Oracle databases. The ODM interface is an Application Programming Interface (API)

that Oracle co-developed with Veritas for incorporating underlying volume managers and file systems.

The implementation of the ODM interface in a file system or a logical volume manager provides many

benefits, including simplified file administration, improved file integrity, and reduced system overhead

that leads to increased performance. The performance improvements are based on the following:

 File System Direct I/O: With this feature, Oracle disk I/O bypasses the HP-UX buffer cache to

provide the following benefits:

– Improved system efficiency: Oracle uses its own buffer (System Global Area (SGA)) to cache disk

I/O and has better knowledge than the HP-UX kernel about which Oracle data objects must be

buffered. Hence, it is more efficient to devote memory to the SGA than to the HP-UX buffer cache

for Oracle databases.

– Improved I/O performance: Without File System Direct I/O, each Oracle I/O would be buffered

twice—once in the SGA and then in the operating system buffer cache. In addition to using the

memory in an inefficient way, this double buffering also consumes additional CPU resources (an

additional memory-to-memory system call is required). Using File System Direct I/O avoids double

buffering and its negative influence on I/O performance.