Re: Oracle DR Solution

  • From: Sanjay Mishra <smishra_97@xxxxxxxxx>
  • To: "Laimutis.Nedzinskas@xxxxxx" <Laimutis.Nedzinskas@xxxxxx>, "oracle-l@xxxxxxxxxxxxx" <oracle-l@xxxxxxxxxxxxx>
  • Date: Wed, 31 Aug 2011 09:02:01 -0700 (PDT)

Thanks Laimutis for sharing your thought. As the environment is 11g R2 and so 
definitely can even have active data gaurd and even can use for Reporting 
purpose. Trying to see what are the advantage of Storage Replication which 
surely need more work on SA side. Never worked with Storage solution and so 
want to see if this is used over Dataguard in Oracle environment and why.


From: "Laimutis.Nedzinskas@xxxxxx" <Laimutis.Nedzinskas@xxxxxx>
To: oracle-l@xxxxxxxxxxxxx
Sent: Wednesday, August 31, 2011 9:17 AM
Subject: Re: Oracle DR Solution

will add my 2 cents based on my very recent experiences.

first, absolutely the best DR solution is the one you have the most
knowledge about.

next come a few technological thoughts:

- active/active is by far the best. Actually, active/semi-active (which is
data guard) is the best in my opinion.
Why - because cold cluster may start or may not. Been there, seen that.
Standby database is allways mounted and running. What you need is to finish
recovery and open it up.

- now active-active (i.e. RAC). Guess that is a valid alternative but I do
not trust it is possible politically to limit your operations to one node
The tempation to use both or more nodes will end up into the fact that if
one data center goes down then your system will simply not perform. Which
may be even worse than a simple downtime.

- more personel is involved - more problems. Storage replication requires
sys/storage admins involvment. Seen that recently - "oops, the other dc's
storage was wrongly configured..."
Actually, the other(failed) dc storage is still beeing replicated after the
failover. We DBA's got all data guard db's up and running in 24h, including
a full standby db restore. Actually, we got all except one standby db's up
and running as soon as the other dc servers where brought up. After that I
became a bigger fan of data guard even though storage replication has it's
nice features too.

brgds, Laimis N


Please consider the environment before printing this e-mail

  From:       jason arneil <jason.arneil@xxxxxxxxx>                             
  To:        saurabhmanroy@xxxxxxxxx                                            
  Cc:        oracle-l@xxxxxxxxxxxxx                                             
  Date:       2011.08.31 15:54                                                  
  Subject:    Re: Oracle DR Solution                                            

One drawback with the dataguard route is the "… no loss or downtime"

Sure data guard and be configured to ensure no data loss, but it can't give
you no downtime.

Is that no downtime really a requirement? If you are serious about that,
you have to go to some form of Active - Active setup across datacentres,
with stretched RAC as a possibility.

I'd also argue that there are few businesses that really in a catastrophic
scenario can't afford a handful of minutes to enact a failover.



On 31 Aug 2011, at 11:35, saurabh manroy wrote:

      Extended/Stretch RAC is a low cost but rather incomplete DR solution.
      Low Cost: In-terms of number of resources need to maintain the
      environment. DataGuard maintenance needs additional skills (apart
      from knowing RAC). Also, not to forget licensing costs for DataGuard.
      Incomplete: Distance between nodes of cluster is still a major
      factor. Though 11g comes with preffred mirror read options, internode
      communication would still be an issue over long distance. So, less
      distance between nodes means, both sites would likely stop
      functioning in situations of: flood, earthquake etc.

      Since Cost is not an issue for Sanjay, Primary DB as a RAC cluster
      and Standby DB also a RAC cluster would be a better solution in my

      Saurabh Manroy

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                  From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:
                  oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of Sanjay Mishra
                  Sent: Tuesday, August 30, 2011 3:28 PM
                  To: oracle-l@xxxxxxxxxxxxx
                  Subject: Oracle DR Solution


                  I am looking to see what is the best option to have DR
                  solution that can be Primary with no loss or downtime.
                  Looking for best practices even it is expensive solution.
                  Appreciate for any document or link as I am sure lots has
                  done work on it. One of the requirement is that database
                  is around 10Tb and transaction logs will be be not more
                  than 50G in an hour.

                  1. Can see 11g Active Dataguard which can be used for
                  Reporting as well as DR solution

                  2. Storage Replication



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