RE: Disaster Recovery Fallback Sites

From: Nick Wagner <Nick.Wagner_at_quest.com>
Date: Tue, 04 Sep 2001 09:32:51 -0700
Message-ID: <F001.00381FA4.20010904091308@fatcity.com>

> Qs. IF THE DATABASE CRASHES IN THE PRIMARY STORAGE ARRAY BOX , WILL IT
> BE COPIED TO THE 2nd REPLICATION ARRAY THEREBY CAUSING IT TOO HOLD A
> CRASHED COPY OF THE DATABASE TOO ?
Yes, if the filesystem replication is synchronous then the target system will have the EXACT same problems as the source.  It is a direct block level replication. So even datafile corruption errors will be propagated. 

SRDF is a very good backup to actual hardware failure... such as a CPU going bad.

Nick

-----Original Message-----
From: VIVEK_SHARMA [mailto:VIVEK_SHARMA_at_infy.com] Sent: Monday, September 03, 2001 1:26 AM To: Multiple recipients of list ORACLE-L Subject: Disaster Recovery Fallback Sites

MY Qs. IN CAPITALS BELOW :-

Storage-Array/OS fail-over :- 
--------------------------
Storage-array vendors, most notably EMC, have taken the concept of

operating system fail-over one step further. Noting the drawbacks of clustered hardware in the area of disaster recovery and rolling upgrades, they have taken the basic fail-over mechanism at the operating system level, and replaced the clustered hardware concept with the idea of replicated storage-arrays.
So, instead of clustered nodes sharing the data by sharing the same physical disk drives, vendors such as EMC introduced storage-array replication. 

All transactions written to one storage-array would be replicated almost instantaneously to another storage-array.

Qs. IF THE DATABASE CRASHES IN THE PRIMARY STORAGE ARRAY BOX , WILL IT BE COPIED TO THE 2nd REPLICATION ARRAY THEREBY CAUSING IT TOO HOLD A CRASHED COPY OF THE DATABASE TOO ? These two storage-arrays can be geographically separated, though the network between them must be extremely large (i.e. OC3 or higher). The computers, then, are not clustered, and do not require the additional hardware and operating system software to achieve clustering. Products include EMC Symmetrix Data Replication Facility (SDRF), and Oracle Support has white papers describing certification testing performed using SDRF at Oracle.

> -----Original Message-----
> From: VIVEK_SHARMA
> Sent: Sunday, September 02, 2001 3:12 PM
> To:   'gajav_at_yahoo.com'; 'ORACLE-L_at_fatcity.com';
> 'oracledba_at_lazydba.com'
> Subject:      Disaster Recovery Fallback Sites
>
>
> Disaster Recovery Fallback Sites :-
> --------------------------------
> What are the Different Solutions/methodologies implemented ?
> Is Standby Database the best Solution ?
> What are the Harware/O.S. Solutions available ?
> Which would be better using Oracle or O.S. Solutions ?
> Any papers , Links , best practices ?
>

-- 
Please see the official ORACLE-L FAQ: http://www.orafaq.com
-- 
Author: VIVEK_SHARMA
  INET: VIVEK_SHARMA_at_infy.com


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Received on Tue Sep 04 2001 - 11:32:51 CDT