Script that duplicates a database using a physical standby RAC as source

 It’s possibile to duplicate a database for testing purposes (it’s an example) using a standby database as source. This allows you to off-load the production environment.

This is a simple script that makes use of ASM and classic duplicate, although I guess it’s possible to use the standby DB for a duplicate from active database.
You can launch it everyday to align your test env at a point in time.

10gR2 RAC hangs and “KSV master wait”

We recently migrated a customer’s 10gR2 RAC on AIX6.1 from GPFS+HACMP to a “basic” Clusterware with datafiles over ASM.
After (many) problems related to various installation bugs (the list of requirements for AIX is very long, incomplete and requires many one-off patches to complete), we had a problem during an import of a new schema: the import hung with no apparent wait events. We found that the event it was waiting for was classified as ‘Idle’:

The on ASM instance:

The problem was related to datafile resize (we use autoextend) and according to MOS, we were encountering a bug:


Shutting down one instance solved the problem. Now we have to avoid autoextend……. We never encountered this bug in many rac installations.

Dataguard check script for Real Application Clusters (MAA)

Two years after my posts:
Quick Oracle Dataguard check script and More about Dataguard and how to check it I faced a whole new Dataguard between two Oracle Real Application Clusters, aka Oracle Maximum Availability Architecture (MAA).

This enviromnent is relying on Windows OS. Don’t know how this could be called “availability” but here we are. I revisited my scripts in a quick and very dirty way. Please consider that I did copy and paste to check the alignment once per thread, but it should be improved with some kind of iteration to check each thread in a more structured fashion.

Please foreward me every improvement you implement over my code: it would be nice to post it here.

Oracle RAC Standard Edition to achieve low cost and high performance

I finished today to create a new production environment based on 2 Linux serverX86_64 and running Oracle RAC 10gR2. (I know, there is 11g right now, but I’m a conservative!)
Wheeew, I just spent a couple of hours applying all the recommended patches!
We choosed 2 nodes with a maximum of 2 multi-core processors each one so we can license Standard Edition instead of Enterprise Edition. 64bits addressing allow us to allocate many gigabytes of SGA. I’m starting with 5Gb but I think we’ll need more. And a set of 6x300Gb 15krpms disks (it can be expanded with more disks and more shelves).
This configuration keeps low the total cost of ownership but achieves best performance.
Due to disks layout, costs and needed usable storage, we had to configure one huge RAID5 on the SAN with multi-path. I decided anyway to create 2 ASM disk groups (ASM is mandatory for Standard Edition RAC), one for the DB, the second one for the recovery area. With spare disks we should have enough availability and even if it’s a RAID5 I saw good write performances (>150M/s).

Welcome new RAC, I hope we’ll feel good together!