We implemented RMAN backup strategy our production instance earlier this week. We had daily logical full database backups scheduled and weekly cold backups for our 9.2.0.8 Production Instance. The Server did not have sufficient resources to be put in archivelog mode, as the server is pretty old. We arranged extra RAM and some space on the server to achieve the same. Why we couldn't upgrade the production database to a new server is another question that might arise in your minds.
It was only while carrying out the RMAN B/R testing that we came to know that we will be missing few features, if we don't have Oracle Database Enterprise Edition. One of them was Cumulative/Incremental Backups. We had no other option but to have daily full database hot backups. We configured recovery window of 2 days for the production hot backups.
We planned the switch to archivelog mode on the Production Instance after office hours, as we had to bounce the instance. We now generate more 1 GB of archvies per day.
We set up the recovery catalog in a separate database on another machine and registered the production instance in the recovery catalog.
I am thinking of setting up another recovery catalog or in the target controlfile to take periodic backup of the Recovery catalog hosting backup information of the Production Instance.
I will update one of the best features I like about RMAN in the post, with some examples.
Do not use catalog server for a catalog server, instead take daily backup both physical and logical.
ReplyDeleteHi Anwar,
ReplyDeleteCould you provide any reasons why not to use catalog for catalog, as Oracle DBA Handbook mentions this.
Regards,
Zaffer Khan
Hmmnn....good question.
ReplyDeleteI did not know DBA handbook mentioned this.
Actually I just thought that if we make a catalog for catalog..then why not make a catalog for that catalog also and so on... :-).
I feel the role of a catalog is to give some relieve to the control file and of course the DBA by storing the scripts.
You may refer to the metalink Doc ID: 452529.1
To be frank In my company, everything is ready made, we have standard scripts for backups we just have to call them and they do the rest. So catalog implementation, I have just tried it at home.
You are infact having first hand experience on that for prduction boxes, please let me know of your findings.
I will be happy to get them.
Regards
Anwar
"Actually I just thought that if we make a catalog for catalog..then why not make a catalog for that catalog also and so on... :-)."
ReplyDeleteYou are right!!! So the catalog to catalog saga continues......
"I feel the role of a catalog is to give some relieve to the control file and of course the DBA by storing the scripts."
Well, that for sure is true. Just to add to it, there are 2 types of information stored in the control file. One which is fixed and other which is reusable (I don't remember the exact terms. I will provide them later today). The Fixed information is that which stores critical information, like database files, redo logs, tablespaces, etc, unless the corresponding object is dropped from the database. The Reusable information are which stores information like archivelog and backup records.
If you've noticed, there is a parameter "control_file_record_keep_time", which I think defaults to 7. What this parameter does is that it helps retain both types of information for 7 days. After which, it overwrites the reusable records in a circular/cyclic fashion.
NAME TYPE VALUE
---- ---- -----
control_file_record_keep_time integer 7
To avoid overwriting the reusable records pertaining to backups, specially when you have Full, Cummulative & Incremental Backups scheduled, it is recommended to have a catalog repository set, instead of using the target database control file.
As far as setting up Catalog for catalog (of production backups) is concerned, it is a recommended practice, if you have the resources available at your luxury.
I will keep you posted. Meanwhile, share your thoughts on the same.
Regards,
Zaffer Khan
Check out "RMAN Recipes for Oracle Database 11g":
ReplyDeletehttp://books.google.com.kw/books?id=qISYkSBV2hgC&pg=PA123&lpg=PA123&dq=oracle+control+file+reusable&source=bl&ots=uTd_5EnHGR&sig=FZ1kkbTU9-NqjjErldFJ518zCWE&hl=en&ei=Jb2fSdqRB4-N_gb2qpTWCw&sa=X&oi=book_result&resnum=6&ct=result