Re: Multiple DBs on One RAC - Adding New Nodes and Different Storage

From: Paresh Yadav <>
Date: Thu, 26 Dec 2013 14:56:14 -0500
Message-ID: <>

Ah node vs node. Ignore my previous message which makes no sense. I read as node = instance.


On Thu, Dec 26, 2013 at 2:52 PM, D'Hooge Freek <>wrote:

> David,
> You will at least need to make the ASM diskgroup holding the voting / ocr
> files visible on the new nodes as well.
> I have never tested what happens if not all ASM diskgroups are visible on
> all nodes, but I would expect to see some errors when creating / mounting
> new disk groups.
> What would be the reason to not have all involved luns visible on all rac
> nodes?
> In my opinion, it would make it easier and flexible to have all asm luns
> visible on all nodes.
> I don't understand what you mean with master node?
> If you want to dedicate one (or more nodes) for a application or database,
> you can use db services. In the service configuration you can mark some
> instances as preferred and other as available.
> There is also no requirement to create an instance on each of the nodes.
> You could for example have the following setup:
> Database A, used by application X has instances on nodes 1,2 and 3.
> The db service used by application X has the instances on nodes 1 and 2 as
> preferred and on instance 3 as available (standby so to speak).
> Dabase B, used by application Y and Z has instances on nodes 3, 4 and 5.
> The db service used by application Y has the instances on nodes 3 and 4 as
> preferred and on instance 5 as available, while the db service used by
> application Z has nodes 4 and 5 as preferred an node 3 as available.
> As you can see, you can play an puzzle with this as much as you want.
> Kind regards,
> --
> Freek D'Hooge
> Uptime
> Oracle Database Administrator
> email:
> tel +32(03) 451 23 82
> On do, 2013-12-26 at 13:22 -0600, David Barbour wrote:
> Merry Christmas (to those of you who celebrate), Happy Holidays (to those
> who may not but have something going on - including New Year's), and Good
> Afternoon:
> We are currently running a 3-node RAC on RHEL 6.3(version
> 2.6.32-279.22.1.el6.x86_64), Oracle on ASM. Storage is
> fibre-connected EMC VMAX. Cluster cache communication is handled via
> Infiband. We are adding a new application and two nodes. The question
> arises with the storage. We're putting the new application on a Dell
> Compellent SAN. Also fibre connected. The plan is to make the 2 new nodes
> the primary nodes for this application, and make node 3 of the current
> cluster the fail-over.
> Can anyone who has used multiple different SANs before provide any
> hints/tips/tricks/pitfalls?
> Will we have to serve the current EMC Storage to the new nodes? I don't
> see why as we're not expanding the number of instances of the currently
> running application. But we will have to zone the new storage to connect
> to the third node of the current cluster. Any thoughts on how to install
> this new application? I don't really want instances of it on Nodes 1 & 2
> at all. If I make Node 3 the master node and install from there, I should
> be able to pick Nodes 4 & 5 on which to create the other new instances.
> Any thoughts?

Received on Thu Dec 26 2013 - 20:56:14 CET

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