clustered server

[d_kishore]

what is the difference between clustered server and parallel server ?

in our comp we are using HP9000 server and OS is unix with RAID 5 technology and i have to install Oracle 8i server and i have to make the disk mirroring.

how to do that.... ?

thank u in advance

bye
kishore

[jlakhani]

You need to follow OFA (Optimal Flexible Architechture) to stripe out your database: datafiles: Indexes, rollbacks, redologs. etc

Please read your Oracle DBA handbook.

[deggzy]

Hi,

If you are running RAID5 then you don't need to mirror. Mirroring is RAID 2.

It should be noted that this type of raid (2) is faster as individual devices can be assigned to various datafiles.

In a RAID5 you cannot assign a file to a particular disk in the array. You can create logical volumes within the array which is not the same thing.

RAID5 will build in more redundancy, if a disk goes the software should be able to re-create that disk on the fly, as in the DB will continue to work as if the disk was still ok.

When you then put a new disk in to replace the broken one you should be able to rebuild that disk with the redundant data stored on the other disks.

[pss]

On my understanding difference between clustered server and parallel server is clustered server is a configuration in which two database instances use two different databases (datafile sets) and have replication between itself and other instance. Parallel server configuration when two or more database instances resides on different nodes of a single cluster with shared disk drives and utilize single database (share database datafiles).
Clustered server configuration may be used for database redundancy (not only disks). Parallel server usually helps to balance your database activities (connections, load balancing).
Based on that you don't need parallel server or clustered server configuration.

Sergey.

[Edited by pss on 02-14-2001 at 11:42 AM]

[LND]

yet another difference is described like that:

the same database (in terms of database files) sitting in RAID can be run by SW residing on two(or more) different nodes. It is essential that instance is active only on one node at a time.

When one node is down (crached of more often under maintanance), the other node activates and database instance is started.

The parallel server allows two instance to run at the same time on several nodes.

[Prasy]

Hai degzzy,

One small correction, Raid 1 is disk mirroring and not Raid 2!!!

[steviep9]

I'm not sure what you mean by clustered servers, but I think
your referring to a cluster solution. In that case, Oracle has 2 solutions.
1. Oracle Fail Safe.
FailSafe uses cluster technology.
Ie Oracle software is installed on 2 nodes and the db resides on a shared disk. If the instance fails on Node A, then the instance on Node B takes over. failSafe does not share the resources between nodes.

Parallel Server in essence in the same but it allows sharing the resources between multiple machines for the same db. I believe 9i will also include Parallel Server Failover (ie with failsafe)...