Oracle Backup

[Siva143]

can any one explain the below question?

In oracle database backup why we need to down all the database servers while we are taking backup ?Why down time should be more than 10 mints?  reason?

[Marianne]

Who says you need to down all the databases?

There are at least 3 ways in which Oracle can be backed up without taking databases down:

1. NetBackup with Oracle agent
   NetBackup integrates with RMAN to take online backup
   One-step backup and restore.
   
   
2. RMAN backup to disk, followed by file-level NBU backup 
   RMAN backup takes place while databases remain online.
   Sufficient disk space must be provided, backup and restore is 2-step process
   
   
3. Database in hot backup mode, combined with snapshot technology.
   If Storage Array snapshots are an option, DB is put into hot backup mode, snapshot is taken, DB taken out of backup mode, followed by NBU backup of the snapshot.
   This method requires custom scripting or NBU Snapshot Client option.

If anyone wants to take file-level backup of Oracle databases, then Oracle MUST be shutdown for the duration of the backup. 
Oracle files are in inconsistent state while databases are online.
Oracle will simply not startup if restore is done from backups while DBs/files were in inconsistent state.

PS:
Please talk to your Oracle DBAs - they will confirm that file-level backup of online DBs are pointless. 

[Michal_Mikulik1]

Hello,

Can you please provide some reference for statements you describe?

Generally said, they are not true at all.

Regards

Michal

[Siva143]

Hello marianne,

               Thanks for you are replying on this 

In my environment we dont have oracle backups,presently am learing oracle backup.

Recently i attended one interview,the interviewer asked me this question .

[Michal_Mikulik1]

Hmm, looks like trick questions only.

As I stated above, there is no need to take Oracle backups offline, unless they must be run in so called NOARCHIVELOG mode for some (usually administration related) reasons.

And question about 10 mins is a nonsense.

Deeper explanations are beyond the purpose of this forum - to study more about this topic is a good idea.

Regards

Michal

[Marianne]

Oh No! PLEASE! No Interview questions here..... 

[Siva143]

Am sorry marianne

i dont know the answer

thats y i posted here,actually am new here

i asked this question  my colleagues also ,they also dont know 

[Siva143]

Hello Michal,

Thanks for you are replying on this

the down time should not be more than 10 mins.

[Michael_G_Ander]

The Oracle Admin guide can probably answer most of you questions.