VERITAS Storage Foundation 4.1 Oracle Administrator's Guide

Chapter 2, Setting Up Databases

Prerelease 8 September 2005, 8:54am Selecting a Volume Layout

Volume Configuration Guidelines

Follow these guidelines when selecting volume layouts:

◆ redo logs - Put the redo logs on a file system created on a striped and mirrored (RAID-0+1)

volume separate from the user tablespaces or data files. Stripe multiple devices to create larger

volumes if needed. Use mirroring to improve reliability. Do not use VxVM RAID-5 for redo

logs.

◆ When normal system availability is acceptable, put the tablespaces on file systems created on

striped volumes for most OLTP workloads.

◆ For most workloads, use the default 64 K stripe-unit size for striped volumes and 16 K for

RAID-5 volumes.

◆ When system availability is critical, use mirroring for most write-intensive OLTP workloads.

Turn on Dirty Region Logging (DRL) to allow fast volume resynchronization in the event of a

system crash.

◆ When system availability is critical, use RAID-5 for read-intensive OLTP workloads to

improve database performance and availability. Use RAID-5 logs to allow fast volume

resynchronization in the event of a system crash.

◆ For most decision support system (DSS) workloads, where sequential scans are common,

experiment with different striping strategies and stripe-unit sizes. Put the most frequently

accessed tables or tables that are accessed together on separate striped volumes to improve the

bandwidth of data transfer.