RE: Hot backups

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Thanks for your input.
 
So basically there is no guaranteed method of ensuring that everything
is in sync, it's just really a case of getting as close as you can.
 
Chuck, you should get a job writing the documentation for oracle as
that's the clearest explanation for this that I've seen.
 
Thanks
 
Brian

________________________________

From: ora-apps-dba-bounce@xxxxxxxxxxxxx
[mailto:ora-apps-dba-bounce@xxxxxxxxxxxxx] On Behalf Of Sriramulu,
Jayakumar
Sent: 19 February 2009 19:30
To: ora-apps-dba@xxxxxxxxxxxxx
Subject: RE: Hot backups



 

"Bottom line, it doesn't matter exactly when the database backup
finishes; what matters is you have brought the recovered (or cloned)
database up to the same point in time as the end of the file system
backup."

 

I agree . But  in either case with hot backup , we cannot get both the
file system and database in sync. ( Even if you recover the database
close to the  point in time when the apps stack backup completed, we
never know when exactly the concurrent logs and out folders are backed
up, so technically the  database  recovery point in time should match
the time when the  concurrent  log and out folders backup completed )

 

  Thanks for the explanation.

 

         Jay

 

________________________________

From: ora-apps-dba-bounce@xxxxxxxxxxxxx
[mailto:ora-apps-dba-bounce@xxxxxxxxxxxxx] On Behalf Of Chuck Edwards
Sent: Thursday, February 19, 2009 1:20 PM
To: ora-apps-dba@xxxxxxxxxxxxx
Subject: Re: Hot backups

 

Starting the database backup later is what can can cause the
inconsistency.

 

As long as you recover the database to a point in time that is close to
when the file system backup is finished, you will have reasonable
consistency between the concurrent manager logs and output and
FND_CONCURRENT_REQUESTS.  If you start a database backup  after the apps
stack, you will have to recover DML to FND_CONCURRENT_REQUESTS that is
not in your file system backup.

 

For example:

 

1.  You back up the file system.  The backup completes at 8:00am.  At
8:00am, the latest concurrent request ID is 90000.

2.  You now start the database backup AFTER completing the file system
backup (8:00am or later).  The db backup completes at 11:00am and the
latest concurrent request ID is now 90500.

3.  When you recover the file system (for a clone or whatever) the
$APPLCSF directories will only contain logs and output up to request
90000 because that was the latest request id at the time the backup
completed.

4.  When you recover the database hot backup, your database will reflect
the concurrent request ID from the END of the hot backup.  90500 in this
case.  You will have lost the actual output and log files of 500
requests, but it will look like they are there in the application.

 

On the other hand:

 

1.  You start a hot database backup that completes at 8:00am.  The last
concurrent request ID is 90000 and the last database log sequence number
is 100.

2.  You then back up the file system, which completes at 11:00am and the
last concurrent request ID is now 90500.  You also note the current
database log sequence number is 112.

2a.  You add database logs 101 - 112 to your already completed hot db
backup.

3.  You recover the file system (for a clone or whatever) and the
$APPLCSF directories contain logs and output up to request 90500 this
time.

4.  You recover the hot database backup ALL THE WAY UP TO LOG 112; The
latest concurrent request ID in FND_CONCURRENT_REQUESTS is now also
90500.  Everything is in sync because you recovered the database to the
same point in time that the file system backup completed.

 

Bottom line, it doesn't matter exactly when the database backup
finishes; what matters is you have brought the recovered (or cloned)
database up to the same point in time as the end of the file system
backup.

 

Hope that helps,

 

Chuck Edwards

Blue Gecko, Inc

http://www.bluegecko.net/oracle-apps-dba

 

 

 

On Feb 19, 2009, at 10:05 AM, Sriramulu, Jayakumar wrote:





I would think taking database hot backup ( at the end  or ) slightly
later  than the apps stack backups would be better as  the   concurrent
jobs' logfile and outfile details would be  in the database this way.
Otherwise the  logfile and outfiles would be in the apps stack backups
but the corresponding  table entries will not be in the database backup.

 

       Thanks,

         Jay

 

________________________________

From: ora-apps-dba-bounce@xxxxxxxxxxxxx
[mailto:ora-apps-dba-bounce@xxxxxxxxxxxxx] On Behalf Of Chuck Edwards
Sent: Thursday, February 19, 2009 9:38 AM
To: ora-apps-dba@xxxxxxxxxxxxx
Subject: Re: Hot backups

 

The order doesn't matter much as long as they are done at roughly the
sane time.  If you are backing up the database hot (which you should)
back up the database first, and capture the last archive log as soon as
the file system backups are complete.  You will the have a complete
backup that includes all database changes up to the completion of your
file system backups.

 

Hot backups will require you to create the database and perform an
incomplete recovery (either manually or via RMAN).  This is not very
difficult and gives you more control over what point in time your clone
represents.

 

One note:  It's rarely necessary to clone the RDBMS_ORACLE_HOME,
IAS_ORACLE_HOME, and 8.0.6_ORACLE_HOME; These file systems do not change
much and application patches do not affect them.  You should back them
up, but there isn't usually a reason to re-copy them to downstream
environments every time you clone unless something has changed (e.g. you
applied an RDBMS patch, a new Developer 6i patchset etc.)

 

Chuck Edwards

Blue Gecko, Inc.

http://www.bluegecko.net/oracle-apps-dba

 

 

 

On Feb 19, 2009, at 1:06 AM, Dwyer, Brian wrote:

 

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North Yorkshire Police monitors all internet email activity and content.

This communication is intended for the addressee(s) only.

Please notify the sender if received in error. Unauthorised use or

disclosure of the content may be unlawful. Opinions expressed in this

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Hello

 

Looking at implementing hot backups on our 11.5.9 system running on
Solaris.

 

Do you backups the APPL_TOP / COMMON_TOP/ IAS_ORACLE_HOME /
8.0.6_ORACLE_HOME / RDBMS_ORACLE_HOME before you backup the database
files or do you do it the other way?

 

And how does a hot backup affect the way that you do a clone?

 

Cheers

 

Brian

 

 

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