rman脱机备份，首先使用rman登入数据库服务器，然后关闭数据库后，启动数据库到mount状态，在执行backup database指定备份整个数据库。
 

1、启动mount归档模式

sys@ORCL>archive log list;
Database log mode           Archive Mode
Automatic archival           Enabled
Archive destination           USE_DB_RECOVERY_FILE_DEST
Oldest online log sequence     1
Next log sequence to archive   2
Current log sequence           2
sys@ORCL>shutdown immediate;
Database closed.
Database dismounted.
ORACLE instance shut down.
sys@ORCL>startup mount; 
ORACLE instance started.

Total System Global Area 3221225472 bytes
Fixed Size            8797928 bytes
Variable Size          788529432 bytes
Database Buffers     2415919104 bytes
Redo Buffers            7979008 bytes