Re: RAC and Data Guard Configuration Question
Date: Wed, 07 May 2008 12:20:44 +0200
Message-ID: <4821827C.1040809@usn-it.de>
Hi Chris,
Chris Dunscombe schrieb:
> On the DR site we only have 3 nodes, we'd like 6 but 3 is all that we're going
> to get.
>
> The question is should we configure DR to have 1 instance per node (same as
> production) but this leaves only a total of 3 instances and hence 3 redundant
> UNDO tablespaces etc or have 2 instances per node?
>
> Also is it best practice to have the instance names on DR the same as in
> production.
>
> Any experiences, advice, "best practice" etc. for this is most welcome.
>
please keep in mind, that the standby database will only use one instance for recovery, so you can use the power of the RAC on standby side after a switchover only. In usual cases this should not be a problem, physical standby recovery is rather cheap.
You don't need to count instances the way you explained - a RAC recovery works very good on a single-instance standby system as well. Given, it has enough power, of course.
Since the physical standby database is only in MOUNT state, the undo tablespace usage does not count.
I assumed physical standby database as desired by you, should you prefer logical stb, things are changing greatly: But in this case, I won't use more instances per node than the production has.
Regards
Martin Klier
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