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RE: oracle rac 10g and OS clusterware.

From: John Hallas <>
Date: Wed, 5 Dec 2007 14:21:09 -0000
Message-ID: <>

Good response Dan. How often does node eviction take place on a 'normal' configuration (if there is such a thing).  

PS I came across an excellent presentation of yours this morning on HA options for Oracle e-db-oow2007-slides.pdf  


[] On Behalf Of Dan Norris Sent: 05 December 2007 03:32
To:; Peter McLarty Cc:
Subject: Re: oracle rac 10g and OS clusterware.  


Oracle Clusterware 10g will always handle node fencing (aka eviction) by rebooting one or more nodes. Oracle didn't have it's own cluster manager software for most platforms on 9i. So, if your customer was on a platform where Oracle didn't have a cluster manager of its own (it only had Linux and Windows), then building the RAC cluster would have required some 3rd party software. Some of the 3rd party cluster managers used different schemes to fence nodes from the cluster. Many of them used I/O fencing which was somewhat less disruptive in that it didn't require a node reboot, but required more proprietary interfaces to be used to access and manage storage.

The answer to your question is that it depends. You will always have to have Oracle Clusterware if you're building a 10g cluster. However, if you additionally use a 3rd party clusterware (one that uses I/O fencing instead of reboots to handle node eviction), Oracle Clusterware will not handle cluster membership and therefore won't impose its "reboot the other node" scheme of node eviction. I should mention that I believe this is true in most cases, but not all cases.

If you use just Oracle Clusterware (which is the only requirement and handles all cluster management needs albeit with using node reboots to evict them from the cluster), you'll be subject to node reboots if node eviction is required.

See Kirk McGowan's post on Oracle Clusterware's node eviction methods at for some additional insight.


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Received on Wed Dec 05 2007 - 08:21:09 CST

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