Re: RAC doubt - CRS

From: Michael Austin <>
Date: Mon, 09 Jun 2008 19:21:04 -0500
Message-ID: <pMj3k.2177$>

DA Morgan wrote:

> wrote:

>> Hi All,
>> I have less exp. with oracle ( 2 year ) and just going through with
>> documentation with RAC.
>> I would thankful if you please clear my one doubt.
>> It is mentioned in documentation ( 10g docs ) that Oracle Clusterware
>> formerly known as Cluster Ready Service.
>> Further going forward, CRS is also shown as a component of Oracle
>> Clusterware.
>> It is not clear to me weather CRS was at TOP ( formerly in 9i, now
>> replaced with Clusterware )
>> level before now it is a just component of Oracle Clusterware ..
>> Regards,
>> Lyxx
> Anything clusterware from 9i was tossed out, including a lot of its
> source code, and rewritten in 10gR1 and then somewhat less in 10gR2.
> The only substantive relationship is the name.

According to some sources, what is now CRS (Cluster Ready Services aka Clusterware) was licensed from HP from the cluster interface in Tru64 UNIX - which was ported from the cluster services in OpenVMS and modified to fit Oracle's needs. The biggest portion of this was the much-needed lock manager to prevent cluster systems from interfering with the writes of other node members- this is known as Cache-Fusion in Oracle. Received on Mon Jun 09 2008 - 19:21:04 CDT

Original text of this message