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Re: single node RAC system?

From: herta <herta.vandeneynde_at_gmail.com>
Date: Thu, 07 Jun 2007 21:58:48 -0000
Message-ID: <1181253528.446469.106400@p47g2000hsd.googlegroups.com>


On Jun 1, 3:00 am, DA Morgan <damor..._at_psoug.org> wrote:
> herta wrote:
> > On Jun 1, 12:52 am, DA Morgan <damor..._at_psoug.org> wrote:
> >> herta wrote:
> >>> On May 29, 5:39 pm, DA Morgan <damor..._at_psoug.org> wrote:
> >>>> herta wrote:
> >>>>> On May 26, 2:25 am, DA Morgan <damor..._at_psoug.org> wrote:
> >>>>>> herta wrote:
> >>>>>>> We are currently setting up our disaster recovery site (DRS).
> >>>>>>> For Oracle, we want to use Dataguard to copy our databases to physical
> >>>>>>> standby databases on asinglesystem at the DRS.
> >>>>>>> Thesinglesystem is quite capable of running the Dataguard load, but
> >>>>>>> should we need to run production at the DSR, it will not suffice. We
> >>>>>>> would therefore like to set up this system assinglenodecluster, so
> >>>>>>> that we can easily add instances if necessary.
> >>>>>>> I tried installing clusterware on asinglenode, but the start of ONS
> >>>>>>> fails with:
> >>>>>>> Start of `ora.l27.ons` on member `l27` failed.
> >>>>>>> CRS-1006: No more members to consider
> >>>>>>> CRS-0215: Could not start resource 'ora.l27.ons'.
> >>>>>>> Metalink article 2411114.1 suggests that the set up is possible,
> >>>>>>> though the environment described there differs from ours (we use
> >>>>>>> 64-bit SLES 10, Oracle RAC 10.2.0.3, ASM).
> >>>>>>> It also warns that "this configuration is not certified or supported
> >>>>>>> by Oracle Support Services".
> >>>>>>> Has anyone tried setting up asinglenodecluster? If so, did you get
> >>>>>>> the ONS error? How did you work around it?
> >>>>>>> As to the support status, in theory, we could set up a twonode
> >>>>>>> cluster, and then take onenodedown. How would that differ from a
> >>>>>>>singlenodecluster configuration?
> >>>>>>> Alternative suggestions to achieve our goals are also welcome, of
> >>>>>>> course.
> >>>>>>> FWIIW, I opened an SR with Oracle four days ago, but they have yet to
> >>>>>>> respond with something other than "we're looking into it'. A previous
> >>>>>>> posting in ORACLE_DBA_EXPERTS also remained unanswered.
> >>>>>>> I'm sort of pressed for time as the goal is to ship this to the DRS in
> >>>>>>> three
> >>>>>>> weeks time, and just getting a first copy of the physical databases on
> >>>>>>> the storage is going to take a while.
> >>>>>>> Kind regards,
> >>>>>>> Herta
> >>>>>> Build a two-nodecluster and then shut down one machine.
> >>>>>> Suggestions that you use VMWare will result in an unsupported environment.
> >>>>>> --
> >>>>>> Daniel A. Morgan
> >>>>>> University of Washington
> >>>>>> damor..._at_x.washington.edu
> >>>>>> (replace x with u to respond)
> >>>>>> Puget Sound Oracle Users Groupwww.psoug.org
> >>>>> Thanks, Daniel. We're considering this, using a test system as our
> >>>>> second member, but we're wondering what impact this would have when
> >>>>> we'd need to upgrade the software. (We cannot ship the test system to
> >>>>> the DR site.) Has anyone actually done this?
> >>>>> Kind regards,
> >>>>> Herta
> >>>> We just got done doing this for a public company where they are
> >>>> doing Data Guard from RAC cluster tosingleinstance but want the
> >>>> ability to quickly turn thatsingleinstance into a cluster by
> >>>> adding nodes.
> >>>> --
> >>>> Daniel A. Morgan
> >>>> University of Washington
> >>>> damor..._at_x.washington.edu
> >>>> (replace x with u to respond)
> >>>> Puget Sound Oracle Users Groupwww.psoug.org
> >>> Yes, I know I can set up a 2-nodecluster, and then remove onenode.
> >>> I took the Oracle RAC course, and removing a system from the cluster
> >>> and adding another one was the last exercise of the training.
> >>> I'm just worried about how we can upgrade that onenode.
> >>> As explained, we want to run Dataguard standby databases on this
> >>> system, and as you may know, Dataguard requires the primary and
> >>> standby databases to run the same software versions. I would hate not
> >>> being able to install a critical patch in production just because it
> >>> cannot be installed on our DR system.
> >>> Oracle has documented setting up asinglenodecluster in Oracle 9i
> >>> without having to start from a twonodecluster.
> >>> My colleague read some Oracle 10g beta documentation with a similar
> >>> setup, but the official documentation does not mention it anymore.
> >>> I tried in vain to install asinglenodecluster, and the 'CRS-1006:
> >>> No more members to consider' error has me worried that even when I'd
> >>> start with a twonodecluster and remove onenode, the onenodewon't
> >>> be upgradeable because it lacks other cluster members.
> >>> Given the changes between 9i and 10g, I am reluctant to follow that
> >>> path without confirmation from Oracle that they will support this
> >>> configuration.
> >>> (Still no word from them after 10 days, though. :-( )
> >>> Kind regards,
> >>> Herta
> >> I'm a bit confused by what is confusing you.

>

> >> A two-nodeRAC cluster is a special case. A cluster, to allow for
> >> rolling upgrades, should be three or more nodes.
> >> --
> >> Daniel A. Morgan
> >> University of Washington
> >> damor..._at_x.washington.edu
> >> (replace x with u to respond)
> >> Puget Sound Oracle Users Groupwww.psoug.org
>

> > Hi Daniel,
>

> > I'm not even worried about rolling upgrades at this stage. Though I
> > didn't know that you couldn't do a rolling upgrade on a two-node
> > cluster. We just moved our production and non-production environments
> > to two-nodeclusters, so this definitely is relevant info for us. Do
> > you remember where you read about this? (If not, I'll hunt around
> > myself, but I'm rather pressed for time right now.)
>

> It isn't that you can't do a rolling upgrade. Rather that when you
> offline onenode... you lose TAF, lose FCF, lose load balancing,
> lose that which makes RAC RAC. You no longer have a cluster.
>

> > About the initial issue: when I try to install asinglenodecluster,
> > the error I get suggests that the installation script is looking for a
> > secondnode,
>

> Which is why I suggested creating a twonodecluster and burning the
> secondnodeto the ground as soon as you were finished or doing a
> shutdown immediate so it isn't live.
> --
> Daniel A. Morgan
> University of Washington
> damor..._at_x.washington.edu
> (replace x with u to respond)
> Puget Sound Oracle Users Groupwww.psoug.org

Ran another cleanup procedure, rebooted the system for good measure, and now the installations runs fine.
I guess the reboot must have cleaned up something that wasn't obvious to me.
Thanks for telling me about the config you did at your client's, Daniel. It's what really convinced me to try again. Thanks to all who posted and mailed suggestions.

Only problem now is getting the listener to work, but I have the same issue in a dual node RAC. Cf.
http://groups.google.com/group/comp.databases.oracle.server/browse_thread/thread/249c6661aa87fed4/98bbd5fb23a225c4?lnk=gst&q=crs_start&rnum=2#98bbd5fb23a225c4

Fwiiw, Oracle support have finally reported back today. They confirm that a single node RAC is a supported configuration.

Kind regards,

Herta Received on Thu Jun 07 2007 - 16:58:48 CDT

Original text of this message

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