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how to backup oracle DB

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Asif_8
Regular Advisor

how to backup oracle DB

Hi !

I have 9i runing no archive mod. How to backup database onlinb. I do not want to stop the database
thanks
10 REPLIES
Luk Vandenbussche
Honored Contributor

Re: how to backup oracle DB

You can take an export of the database and put the export on a tape
spex
Honored Contributor
Solution

Re: how to backup oracle DB

Hello,

If I were you, I would enable ARCHIVELOG mode and take regular, hot backups. This involves copying datafiles and archivelogs to secondary storage. Your procedure should also include exporting the SQL necessary to re-create your controlfiles via 'ALTER DATABASE BACKUP CONTROLFILE TO TRACE...'.

Alternatively, if you can afford a little downtime every night (on the order of a few minutes), you could take VxFS snapshots of the relevant filesystems. You would then be able to back up the snapshots to secondary storage at your leisure. See A. Clay's article from SysAdmin Magazine here:
http://www.samag.com/documents/s=7898/sam0304a/0304a.htm

This "cold" backup method requires you to carve up the necessary snap filesystems (each should be 15% the size of its source filesystem), as well as purchasing the retail version of OnlineJFS.

"Oracle Backup and Recovery FAQ":
http://orafaq.com/faqdbabr.htm

"Oracle9i Backup and Recovery Concepts":
http://download-east.oracle.com/docs/cd/B10501_01/server.920/a96519/intro.htm

PCS
Vladimir Fabecic
Honored Contributor

Re: how to backup oracle DB

You can also use Oracle RMAN. It can backup on-line.
In vino veritas, in VMS cluster
Yogeeraj_1
Honored Contributor

Re: how to backup oracle DB

hi,

One precision that you may find useful: We need a database to be in archive log mode for hot backups (regardless of whether you
use RMAN or the old fashioned way). We need this because the copies of the files we make
during this time are "fuzzy" or inconsistent. We need the archived redo logs to make the consistent again.

In Oracle 10g, this all changes with the ability for rman to catch up your backups and for the incremental to read ONLY changed blocks instead the entire database...

For background information, please read:

http://otn.oracle.com/docs/products/oracle9i/doc_library/release2/server.920/a96566/rcmconc1.htm#462102

kind regards
yogeeraj
No person was ever honoured for what he received. Honour has been the reward for what he gave (clavin coolidge)
Asif_8
Regular Advisor

Re: how to backup oracle DB

thanks every one

Now problem is this

1. DB in no archive mode
2. we do not change the mode now
3. we can not shutdown the db

in This condition
1.what is best solution ?

2.can i do rman backup nocatalog ?
Yogeeraj_1
Honored Contributor

Re: how to backup oracle DB

Hi again,

With these limitations, you should understand that you will LOSE your database some day and have to revert back to the last full backup. Not might, it is more a matter of time. So please make sure that losing say the production instance and all work done for a day is OK.

In order to backup (without RMAN) you will follow the steps in:

http://download-west.oracle.com/docs/cd/A87860_01/doc/server.817/a76993/toc.htm

The ideal solution is run in archive log mode and do HOT backups using RMAN(never ever shutdown). You should at least be able to do ONE shutdown!! After that all you worries would be gone...

hope this helps!

kind regards
yogeeraj
No person was ever honoured for what he received. Honour has been the reward for what he gave (clavin coolidge)
Volker Borowski
Honored Contributor

Re: how to backup oracle DB

Well with this:

1. DB in no archive mode
2. we do not change the mode now
3. we can not shutdown the db

You will NOT be able to do a backup!

The only possibility in this situation is to do an export, which you never should consider to be any kind of backup, esp. if the application is still modifing data while the export is running.

Consider this as a a VERY risky situation!

In case you are telling us, that it will not be possible to bring the database offline for some 5 minutes to toggle the log mode, you are in trouble.
Sorry for telling the truth.

In case your "database" is very small and consists of only a few tables, you can try do create a diffrent (second) database runnig in archivelogmode and try to move the tabledata using dblinks. But you will face availability problems, if you set locks to all tables to get a consistent copy to the other database. All in all I'd consider the efford when using this method as too costy, esp. as you are not getting a real backup solution out of it compared to 5 min. downtime and never have a problem again...

Volker
Jov
Honored Contributor

Re: how to backup oracle DB

>> We need a database to be in archive log mode for hot backups (regardless of whether you use RMAN or the old fashioned way).

You dont need Oracle to be in Archive Log mode for RMAN, the trade-off is you will not be able to perform point-in-time restore of the database instance.


Jov
Volker Borowski
Honored Contributor

Re: how to backup oracle DB

Jov,

according to this document

http://download-uk.oracle.com/docs/cd/B19306_01/backup.102/b14192/intro005.htm#sthref70

Section 1.5.3.1 clearly points out that the database needs to be in archivelog mode to use online or so-called inconsistent backups.

Beside this, the entire document is pretty usefull and can be entered here:
http://download-uk.oracle.com/docs/cd/B19306_01/backup.102/b14192/toc.htm

Best regards
Volker
Jov
Honored Contributor

Re: how to backup oracle DB

Volker,

Yes, you're right, even using RMAN without archivelog mode, closing the db is required for a consistent backup.

The source where I read incremental backup is possible with noarchivelog mode was also referring to offline backup where I interpreted as online incremental.

Where as point-in-time or incomplete recover meant you can recover the database to any given time up to the time of last backup.


Jov