RE: Oracle DB Backups on SAN with ALTER SYSTEM SUSPEND

Jeremiah,

No, we don't use suspend since these split/hot backup scripts have been in use since V8.0 and I saw no advantage to using suspend. As you say, taking production out of action for no good reason. With regards to using a split controlfile, do you believe there is a difference between this and using a controlfile after a hard system crash? In both cases, consistency will depend on wheather a write to disk was ongoing or completed. I'll have to check with the guru to see if the split code would interrupt a write in progress. In the 4-5 years that we have been creating a reporting instance this way (on a daily basis), nearly all failures could be attributed to bad disks, and this instance is not critical.

On the other hand production backups use the same method. I checked my scripts and while the comments say I backup the controlfile, the code does not. I will definitely correct this. Thanks for emphasizing the need for a binary controlfile as part of a complete hot backup.

Mike Hand
Polaroid Corp.

-----Original Message-----
Sent: Wednesday, March 26, 2003 7:24 PM
To: Multiple recipients of list ORACLE-L

Michael,

Your split is no different from a very fast hot backup. So, it does not matter that the split is not atomic. Just use hot backup mode, and generate a binary controlfile using backup controlfile to 'file' and copy it to your destination. A the destination just recover the one or two logs generated while you did the split. Forget about suspend, it serves no purpose and is just decreasing your system's availability. BTW, your current hot-live copies of controlfiles are potentially invalid and totally unsupported.

All that expensive equipment and you're suspending! Don't take the thing out of service unnecessarily!

--
Jeremiah Wilton
http://www.speakeasy.net/~jwilton

On Wed, 26 Mar 2003, Hand, Michael T wrote:



> Jeremiah,

> The only reason I could forsee is if the split is not atomic.  This is the

> case

> in our (Non-SAN) environment.  The split takes several minutes and the

> control

> files have been mis-matched when the DB copy was started on the reporting

> server.

> My solution under V8.0 was to use only one of the control files for

> reporting

> database.

> 

> My $0.02

> Mike Hand

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-- 
Author: Hand, Michael T
  INET: HANDM_at_polaroid.com

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