Re: Combining snapclones with DataGuard

From: ddf <oratune_at_msn.com>
Date: Mon, 20 Oct 2008 13:20:36 -0700 (PDT)
Message-ID: <cf034264-44c9-4db4-a704-254232000462@c22g2000prc.googlegroups.com>


On Oct 20, 2:17 pm, macdba321 <macdba..._at_gmail.com> wrote:
> On Oct 20, 3:07 pm, ddf <orat..._at_msn.com> wrote:
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> > Comments embedded.
> > On Oct 20, 12:46 pm, macdba321 <macdba..._at_gmail.com> wrote:
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> > > On Oct 20, 1:01 pm, sybra..._at_hccnet.nl wrote:
>
> > > > On Mon, 20 Oct 2008 09:17:41 -0700 (PDT), macdba321
>
> > > > <macdba..._at_gmail.com> wrote:
> > > > >I read quotes from Ari Kaplan explaining how enterprises if possible
> > > > >should (if possible and appropriate) combine the use of snapclones
> > > > >(for SAN-to-SAN replication) with DataGuard.
>
> > I saw no such quotes in the article, nor any in the PowerPoint
> > presentation.  Perhaps I missed something ...
>
> > > > >I am confused how an organization could use both of these though. If I
> > > > >am using snapclones, how can I also use DataGuard? What use would DG
> > > > >provide? (Assuming that I am already snapclone'ing the database to the
> > > > >secondary site.)
>
> > > > >Can anyone shed some light for me?
>
> > > > >Thanks.
>
> > > > Shedding light won't be possible.
> > > > You assume we know your version and you don't provide the URL to Mr.
> > > > Kaplan's article, which might not have been read by everyone and/or
> > > > the less than 10 people here answering questions.
> > > > If you provide that little information, you might consider not posting
> > > > your question at all.
>
> > > > --
> > > > Sybrand Bakker
> > > > Senior Oracle DBA
>
> > > Perhaps it's my mistake, however, I thought it was a generic topic
> > > ("How an organization would make use of both DG and snapclones") It is
> > > not specific to Mr. Kaplan's article/presentation.
>
> > Only from storage vendors trying to make a sale.
>
> > > ]My specific version
> > > of my database/SAN is definitely not applicable.
>
> > To the contrary it certainly IS applicable, as different releases of
> > Oracle implement changing DataGuard functionality, and some of that
> > newer functionality may be necessary to implement this configuration
> > about which you inquire.
>
> > > However, Mr. Kaplan's related info can be found:http://searchstoragechannel.techtarget.com/news/article/0,289142,sid9...
> > > andhttp://www.laoug.org/Download/07q1t2s3.ppt
>
> > > Apologies if this info was needed to help put the question into
> > > context.
>
> > > If yourself and/or anyone else can shed some light on why or how an
> > > organization would effectively use snapcloning and DG simultaneously,
> > > I would appreciate it.
>
> > And we'd appreciate you including your Oracle release information, as
> > it's far more important than you think.
>
> > > Thanks.- Hide quoted text -
>
> > > - Show quoted text -
>
> > David Fitzjarrell
>
> Let's assume I'm on the latest & greatest version of 11g on the latest
> & greatest release & patchset for Windows 2003 64-bit. The SANs are
> the latest & greatest EMC enterprise-class SANs. I'm using the version
> of Data Guard that comes with the latest & greatest 11g for Win 2003
> 64-bit.
>

Condescension does not promote an atmosphere of assistance, and assumptions can fly out the window with amazing speed. Since you'll not provide any actual information I have no other choice but to fly with the 'assumptions' you've made.

> On slide #12 of Mr. Kaplan's presentation he lists the pros of DG.
> "PROS:
> Synchronous mode enables quick recovery with no loss of data
> -Alternate database is already up and running and in sync
> -Works well in conjunction with SnapMirror (array-based replication)"
>
> My question is regarding clarification of the last line of "pros" on
> slide 12. It's hard to imagine Ari being a storage vendor trying to
> make a sale, so what might he be referring to?- Hide quoted text -
>

A basic understanding of SnapMirror might be helpful to you, since SnapMirror is a NetApp product designed to replicate data from a source filer to one or more destinations, even geographicaly dispersed locations. Since in DataGuard synchronous mode the data is already in sync with the source, keeping copies of that data in sync with the DataGuard destination is a simple task (according to NetApp). Thus, having multiple copies of the DataGuard database ready to restore with minimal notice and, apparently, downtime would be beneficial to an enterprise. This would not be possible with some older versions of DataGuard (such as that for 9i and 9iR2) as they have no synchronous mode in which to run. Thus *knowing* the release of Oracle in use (and *not* relying upon condescending assumptions) is a key to a proper and usable response.

> - Show quoted text -

David Fitzjarrell Received on Mon Oct 20 2008 - 15:20:36 CDT

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