Disaster Recovery

[former_member228881]

Hello,

Last week my company's production system got down all of a sudden and we are in the situation where we made our DR server to act as a primary. After 3 days we made our production system up and our primary oracle database was working fine. Then oracle DBA administrators told there is no other way we need to restore the primary database with DR latest backup, since DR is up. So here my question is instead of restoring the whole database is there any other way to recover it?

Regards,

Rajith Kannan R S

[Former Member]

This message was moderated.

[former_member228881]

Hello Jamie,

After we made DR server to act as primary, We swiched on the PRD server after 3 days and found it was very fine except the last 3 days datas are missing. Now my question is why do we need to take the full backup of DR and restore the database with PRD? Is there any other way apart from doing this?

Regards,

RaJiTh R s

[former_member182657]

Hi Rajith,

As per me your DBA configured the database for "Managed Recovery Mode".Please confirm ? In this scenarios your standby database would be under mount state (Not under open state) for the application of redo logs from primary to standby site.

On primary database failure you need to open the standby database which was previously under mount state to act as primary for you.Now currently your standby site is open to act as primary server then we've no other method to recover your primary in this case .For the same as above suggested you need to restore your primary server DB with your standby server DB (Acting currently as Primary) and reconfigure the systems for Managed recovery mode.

In addition for future requirements try to configure oracle data guard broker setup and configure DGMGRL options.

Hope this will help you.

Regards,

Gaurav

[former_member228881]

Hello Gaurav,

Yes it was in managed recovery mode only. Whatever you told was exactly the same told by DBA administrators, Could you please explain why do we need to restore the whole database of primay with DR? And is there any other way? Why can't we apply the last 3 days DR redo logs in primary and make it as primary again?

Regards,

RaJiTh R S

[tamil_arasan]

Hi Rajith,

What DBA guys suggested is correct. Your DR was acted as primary for few days. Transactions were executed in the DR since primary was not available. Now primary is up and running so you have to restore latest backup of DR to primary to avoid the data loss.

Once restore is done, you have to configure the DR setup.

Kind regards,

Pradeep

[former_member228881]

Hello Pradeep,

Could you please explain why DBA guys suggested is correct? Why cant we take incremental backup or apply the redo logs of DR to Primary?

Regards,

RaJiTh R s

[Former Member]

Rajith I'm not totally clear on the scenario -

so the Prod system was recovered on the DR server - OK

What happened next exactly? If you managed to bring it up why do you need to recover it again?

The key is that this sentence - "Then oracle DBA administrators told there is no other way we need to restore the primary database with DR latest backup, since DR is up"  - doesn't entirely make sense to me - can you explain it differently?

Please add a bit more meat to the detail and I'm sure the community can give some helpful advice

Cheers, Jamie AKA doonan79

[Former Member]

Hi,

We have two scenarios where we can start DR site

- Switchover (any Planned activity on Primary)

- Failover (Primary unavailable due to H/w or any other major issue)

In case of Failover, once your DR server takes the role of Primary, there will be no relation with your old Primary.  Your DR server will act independently, it will not recognise your old primary.

In this case you need to reconfigure your DR again.

Regards

[former_member228881]

Hello Shri,

We have successfully switched on our Primary server after 3 days. Here My question is why do we need to restore the primary server from DR server full backup? Why can't we take incremental backup and restore the last 3 days database alone?

Regards,

RaJiTh R s

[former_member188883]

Hi Rajith,

How is the DR configurred and synched up ?

Are you using Oracle data guard ?

Regards,

Deepak Kori

[former_member228881]

Hello Deepak,

We are have configured using Oracle data guard only.

Regards,

RaJiTh R s

[former_member188883]

Hi Rajith,

As you have Oracle dataguard , switching of roles should suffice. There is no need for whole database restore and re-configuing dataguard.

Refer oracle document on the same.

http://docs.oracle.com/cd/E11882_01/server.112/e41134/role_management.htm#SBYDB00600

Hope this helps.

Regards,

Deepak Kori