We are planning to go for RAC for our DSS Type(Decision Support System) databases with ASM. I want some input from you as far as ASM configuration is concerned.
How many diskgroups are common to have in a database? I know Oracle prefers two - one for data & one for FRA(Flash Recovery Area). We have about 200 disks on EMC currently. So, external redundency if we continue with EMC Raid. Then, are we to put all the disks on one diskgroup?[ We currently have about 65 Volume Groups]. While I do not have the disk size exactly for each of them, I am sure they are of different properties - size, speed etc. Am I to put all of them into one diskgroup? Any changes to disk group - if I have one disk group - will affect whole of the databases, because of rebalancing, will it not? Am I not better served in having more than one diskgroup?
How many disk groups do you have in your implementation? Can you tell me the size of the database? Have you gone for external redundancy? Any issues there?
Our main database will be about 3.5 TB in size.