The following recommendations ensure optimal layout of VxVM/CVM volumes:

• Mirror the volumes across two or more storage arrays, if using VxVM mirrors. Keep the Fast Mirror Resync regionsize equal to the database block size to reduce the copy-on-write (COW) overhead. Reducing the regionsize increases the amount of Cache Object allocations leading to performance overheads.

• Separate the Oracle recovery structures from the database files to ensure high availability when you design placement policies.

• Separate redo logs and place them on the fastest storage (for example, RAID 1+ 0) for better performance.

• Use "third-mirror break-off" snapshots for cloning the Oracle log volumes. Do not create Oracle log volumes on a Space-Optimized (SO) snapshot.

• Create as many Cache Objects (CO) as possible when you use Space-Optimized (SO) snapshots for Oracle data volumes.

• Distribute the I/O load uniformly on all Cache Objects when you create multiple Cache Objects.

• Implement zoning on SAN switch to control access to shared storage. Be aware that physical disks may be shared by multiple servers or applications and must therefore be protected from accidental access.

• Choose DMP I/O policy based on the storage network topology and the application I/O pattern.

• Exploit thin provisioning for better return on investment.