In my previous article I have covered, overview of RMAN, Various components of RMAN, and how to start and connect with database.
In this article, I am going to cover how to backup database with the help of RMAN backup utility in Archive log and NoArchive log mode.
We can backup database file with the help “backup database” RMAN command. This will backup your database files to already configured device type. i.e. Disk or SBT, default is Disk.
With RMAN, we backup database as “backup set” OR backup database as “backup as copy”. While backup, by default RMAN creates “backup sets”, backup sets consist of backup piece[s], backup piece means physical file genrated and readable by only RMAN.
With the help of “backup as copy” RMAN command, we can backup database as copy of that database, In which each files would be copy as image. Image copy are similar to copies generated with OS command like cp/copy. Usable by RMAN only. We can use “backup as copy” while database in open mode.
Lets Consider hands-on on Database backup in NoArchive log mode:
While database is running under NoArchive log mode, than only way to consider consistent backup is to take your database in mount state after consistant shutdown. ( i.e. ‘shutdown’ OR ‘shutdown immediate’ ) So that restoring database backup would not required any kind of recovery.
To backup your database in NoArchivelog mode ( i.e. consistent backup ), consider following:
Switch to oracle user:
[root@ol11g ~]# su - oracle
Connect to database and shutdown database consistently:
-bash-4.1$ sqlplus / as sysdba
SQL> shutdown immediate; Database closed. Database dismounted. ORACLE instance shut down.
Start your database in mount state:
SQL> startup mount; ORACLE instance started. Total System Global Area 442601472 bytes Fixed Size 2214176 bytes Variable Size 331351776 bytes Database Buffers 104857600 bytes Redo Buffers 4177920 bytes Database mounted. SQL> exit
Connect to RMAN prompt with target database ( i.e. galaxy ) and start database backup:
-bash-4.1$ rman target / connected to target database: GALAXY (DBID=3647455456, not open) RMAN> backup database;
RMAN> backup as copy database;
Lets Consider hands-on on Database backup in Archive log mode:
To backup your database in archive log mode, your database must be configured in archive log mode. If not, follow my one of the article to convert database in archivelog mode.
As we know, Redo logs are required at the time of recovery to open database in consitent state, thats why we called this backup as inconsistent.
To backup database along with archive log, issue the following RMAN command:
RMAN> backup database plus archivelog;
These is all about backup database with the help of RMAN backup utility in Archive log and NoArchive log mode.
Kindly stay tuned for my next article: How to take oracle database incremental backup with RMAN backup utility – RMAN Part-3