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Re: Advice for setting up single node RAC database

From: Alex Gorbachev <>
Date: Fri, 9 Jun 2006 20:40:31 +0200
Message-ID: <>

A bit late but still...
To move non-RAC database to RAC you will need to add more redo threads (one per instance), more undo tablespaces (one per instance), change init.ora parameter (cluster_database).

To have more redo threads - your controlfile has to have high enough MAXINSTANCES. You can create it in the beginning accounting for RAC, Otherwise, you will have to recreate it manually. Than you just need to add more groups for corresponding redo thread. This is online.

Adding more UNDO tablespaces is also online.

Changing cluster_database to true requires a bounce. You will have to set some instance spacifi parameters - instance_number, instance_name and some instance specific parameters depending on your configuration.

If you are on 9i than you will need to make sure your binaries are compiled with RAC option (if not from the very beginning). In 10g you will have to install CRS and new "cluster-aware" Oracle home.

To conclude, you don't need to take care about anything now. Perhaps, set MAXINSTANCES to number of nodes you plan to have later to avoid recreating controlfile. The rest is done later online (except one restart). You will probably have much more headache with infrastructure evolution - it has to be shared storage so you need to use raw devices from the beginning or cluster filesystem or ASM. However, you can also use normal non-clustered FS and later during migration to RAC copu datafiles to shared storage.

There are plenty of option depending on your setup needs and etc. Good question to ask is do you really need RAC? See, for example,

2006/6/7, Steve Perry <>:
> I had a request to install a database on a single node that, if
> required, can have another node setup and added (i.e. 2 node cluster).
> Has anyone done this before?
> I thought I would ask before taking apart my lab.
> thanks.
> steve
> --

Best regards,
Alex Gorbachev
Received on Fri Jun 09 2006 - 13:40:31 CDT

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