Re: Oracle DR Solution
From: <Laimutis.Nedzinskas_at_seb.lt>
Date: Wed, 31 Aug 2011 16:17:49 +0300
Message-ID: <OF4576E52D.6B5FD684-ONC22578FD.0048026D-C22578FD.00490B65_at_seb.lt>
will add my 2 cents based on my very recent experiences.
Date: Wed, 31 Aug 2011 16:17:49 +0300
Message-ID: <OF4576E52D.6B5FD684-ONC22578FD.0048026D-C22578FD.00490B65_at_seb.lt>
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 only. 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_at_gmail.com>
To: saurabhmanroy_at_gmail.com
Cc: oracle-l_at_freelists.org
Date: 2011.08.31 15:54
Subject: Re: Oracle DR Solution
One drawback with the dataguard route is the "� no loss or downtime" requirement.
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.
jason.
-- http://jarneil.wordpress.com. 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 opinion. Regards, Saurabh Manroy http://smanroy.wordpress.com. the reader of this email (and attachments) is not the intended recipient, you are hereby notified that any dissemination, distribution or copying of this communication is strictly prohibited. Please notify the sender of the error and delete the e-mail you received. Thank you. From: oracle-l-bounce_at_freelists.org [mailto: oracle-l-bounce_at_freelists.org] On Behalf Of Sanjay Mishra Sent: Tuesday, August 30, 2011 3:28 PM To: oracle-l_at_freelists.org Subject: Oracle DR Solution Hi 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 Rgds Sanjay This email and any attachments are confidential and may also be privileged. If you are not the addressee, do not disclose, copy, circulate or in any other way use or rely on the information contained in this email or any attachments. If received in error, notify the sender immediately and delete this email and any attachments from your system. Emails cannot be guaranteed to be secure or error free as the message and any attachments could be intercepted, corrupted, lost, delayed, incomplete or amended. Standard Chartered PLC and its subsidiaries do not accept liability for damage caused by this email or any attachments and may monitor email traffic. Standard Chartered PLC is incorporated in England with limited liability under company number 966425 and has its registered office at 1 Aldermanbury Square, London, EC2V 7SB. Standard Chartered Bank ("SCB") is incorporated in England with limited liability by Royal Charter 1853, under reference ZC18. The Principal Office of SCB is situated in England at 1 Aldermanbury Square, London EC2V 7SB. In the United Kingdom, SCB is authorised and regulated by the Financial Services Authority under FSA register number 114276. If you are receiving this email from SCB outside the UK, please click http://www.standardchartered.com/global/email_disclaimer.html to refer to the information on other jurisdictions. -- Niall Litchfield Oracle DBA http://www.orawin.info -- http://www.freelists.org/webpage/oracle-lReceived on Wed Aug 31 2011 - 08:17:49 CDT