Installation guide

Oracle10g and ASM
All of the recommendaons listed above apply to Oracle9i or Oracle10g ulizing the Oracle Cluster File System. However, if the
Automac Storage Management opon is used for Oracle10g, the rules may need to be modied. With ASM, Oracle soware can
take on the responsibility for managing disk mirroring and striping. You could go as far as giving Oracle a group of individual raw disks
without any hardware RAID. In this case, Oracle ASM could provide soware-based mirroring and striping.
You can specify how many disks that you want to include in the ASM group and the desired level of redundancy (disk mirroring). The
redundancy level can be set at Normal (two-way disk mirrors), High (three-way disk mirroring), or External Redundancy (rely on
hardware disk mirroring). For Dell external storage arrays, it is recommended that you choose External Redundancy. This is
recommended because hardware mirroring is generally more ecient than soware mirroring, and puts less load on the servers.
The algorithm used for soware striping in ASM is somewhat unique. Striping is handled on a per le basis, so that each table, redo
log, etc. may be striped across a dierent number of disks. While soware-based disk striping is inherently less ecient than
hardware-based disk striping, the sophiscaon of the automated striping algorithm makes ASM worth checking out. If you are going
to use ASM striping, you should provide mulple small RAID groups. These groups can be RAID 1 disk pairs, or small RAID 5 or RAID
10 groups. For opmal performance with ASM, congure mulple small RAID 10 groups (such as four disk groups). This provides ASM
striping across hardware striped groups, for a “stripe on stripe” conguraon.
Field experience has shown that ASM can oer good performance, if the disk array is large enough. The soware striping algorithms
tend to work best with the availability of sixteen or more disks in the ASM group. For installaons with less than sixteen disks
(counng only the disks assigned to ASM), the Oracle Cluster File System may oer relavely beer performance.
Although ASM may or may not be benecial to performance in individual cases, it is important to remember that performance is not
the main focus of ASM. ASM is designed to simplify Database Administraon. With ASM, the DBA no longer has to worry about
how to layout Oracle data. Oracle ASM soware automates the process of data placement.
ASM will provide the greatest benet to companies with less experienced DBA sta or limited DBA sta. Some experienced DBAs may
prefer to manage disk striping and redundancy without ASM. The real benet of ASM is giving companies the choice to completely
automate storage management or to manually control storage as they desire.
Seng Up Networking
As seen above, you must set up access to the public LAN through one of the NIC cards on each server before you can fully complete
the cluster setup. This is easily accomplished through seng TCP/IP opons in the Windows Network Sengs interface. Be sure to
check Windows Network Properes to ensure that the Public IP is listed at the top. The Private NIC(s) should always be listed below
the public IP. To check, run the following command to verify that the public IP address is listed rst: