Improving the performance of single instance Oracle on file systems, January 2008

Executive summary

An Oracle® database that runs on a file system is easier to manage than one that uses raw partitions

or volumes, but raw volumes or partitions are often chosen because file systems are generally slower.

However, Oracle Disk Manager (ODM) can bridge this gap in performance, making file systems an

acceptable choice.

This white paper quantifies the performance that can be achieved in an Oracle single-instance

database environment when using:

• A file system without ODM

• A file system with ODM, as provided in HP Serviceguard Storage Management Suite (SG SMS)

Oracle bundles

• Raw volumes, rather than a file system

Two benchmarks were performed: one with Oracle Database 9.2.0.7 and another with Oracle

Database 10.2.0.2.

All known bottlenecks in the system were eliminated, so the only factor that limited transactions per

minute (at a high workload) was the performance of the I/O subsystem or the CPU capacity of the

Oracle server.

The I/O subsystem configurations tested were:

• Online JFS, with and without ODM enabled, configured on Veritas Volume Manager (VxVM) or

Logical Volume Manager (LVM)

• Raw volumes, with VxVM or LVM

The results show that using ODM provides a valuable improvement in the performance of file system-

based environments.

The key findings of this paper are as follows:

• For Oracle 9i and 10g tests, raw LVM volumes showed the highest level of performance.

• For Oracle 9i tests, a performance degradation of 90-95% is seen when using a file system

environment without ODM, compared to the performance of raw volumes. A performance

difference of 68% was measured in the Oracle 10g benchmark.

• If ODM is used with the file system as provided in SG SMS for Oracle bundles, the performance

degradation is only 8-10% compared to raw volumes.

Thus, using ODM with the file system provides performance very close to the performance of raw

volumes.

For many, the manageability benefits of deploying an Oracle database in a file system-based

environment offset the small performance degradation and provide the best deployment option.

For a description of the bundles that contain ODM, see Appendix A.