In this article I will schedule periodic hot backups of a running database instance using RMAN.
To perform hot backups using rman, first you need to check if your database is in ArchiveLog mode.
[[email protected] ~]$ sqlplus “/ as sysdba”
SQL> SELECT log_mode FROM v$database;
LOG_MODE
NOARCHIVELOG
If not change it:
SQL> SHUTDOWN IMMEDIATE;
SQL> STARTUP MOUNT;
SQL> ALTER DATABASE ARCHIVELOG;
SQL> ALTER DATABASE OPEN;
SQL> SELECT log_mode FROM v$database;
LOG_MODE
ARCHIVELOG
Once it’s in ArchiveLog mode create the main rman script which will be called by crontab:
[[email protected] ~]$ vi /u01/rman_main
ORACLE_HOSTNAME=db1
export ORACLE_HOSTNAME
ORACLE_UNQNAME=orcl
export ORACLE_UNQNAME
ORACLE_BASE=/u01/app/oracle
export ORACLE_BASE
ORACLE_HOME=/u01/app/oracle/product/11.2.0/db_1
export ORACLE_HOME
ORACLE_SID=orcl
export ORACLE_SID
/u01/app/oracle/product/11.2.0/db_1/bin/rman target=/ @/u01/rman_script
Where ORACLE_HOSTNAME is your machine hostname and ORACLE_UNQNAME and ORACLE_SID is the SID of the instance you need to backup.
[[email protected] ~]$ chmod a+x /u01/rman_main
Then we create the rman script itself:
[[email protected] ~]$ vi /u01/rman_script
run {
allocate channel ch1 type disk format ‘/u01/backup%d_DB_%u_%s_%p’;
backup database;
backup archivelog all;
release channel ch1;
}
This will backup the database creating a file under “/u01/” directory.
In the above script %d, %u, %s, %p are substitution variables for generating unique file name, if you wish to know more about these variables have a look HERE.
You could manually run rman_main to take hot backups, but if you like to run scheduled backups we need to add this to crontab:
[[email protected] ~]# crontab -e -u oracle
I will schedule backup everyday at 18:10 (6.10 PM)
10 18 * * * /u01/rman_main
The first five fields are:
minute (0-59)
hour (0-23)
day of the month(1-31)
month of the year (1-12)
day of the week (0-6 with 0 = Sunday)
For more info on crontab have a look at crontab.org
NOTE: At first I was unable to edit this file, so after a brief search I had to set EDITOR variable according to my preferred file editor.
In my case:
[[email protected] ~]# export EDITOR=nano
[[email protected] ~]# crontab -e -u oracle
That’s all!!
