We recommend managing your database storage in Oracle's
Automatic Storage Management. Some of the benefits of using ASM include:
- Improved I/O performance and scalability
- Simpler database administration tasks
- Automatic I/O tuning
- Reduction in number of objects to manage
We strongly encourage you to read the many ASM white
papers and documents on Oracle's Web site. In addition, most
storage vendors have written best practice papers on how to configure
ASM for their storage products.
The following are specific ASM recommendations that
we have found to be critical for performance:
- For HP-UX, we recommend importing only raw-devices
into ASM. As we discussed in Max_async_ports, disk_asynch_io above, HP-UX only supports asynchronous I/O
on files that are on raw devices and not filesystems.
- For high volume processing environments, ensure
ASM is configured with "disk" devices from high-performance disk storage
arrays. Some characteristics that you should look for include large
NVRAM caches to buffer disk reads and writes, efficient RAID implementation,
etc.
- Configure ASM with "External Redundancy" so that
redundancy is provided by your storage array instead of being implemented
by Oracle. This setting will eliminate the extra overhead in Oracle
to maintain redundancy.