一、先进行脱机的物理全备操作

# 关闭数据库
[dmdba@alldb ~]$ DmServiceDMSERVER stop
DmServiceDMSERVER service is stopped.

# 确保dmap进程服务启动
[dmdba@alldb ~]$ DmAPService status 
DmAPService (pid 57900) is running.

# 使用dmrman进行物理全备
RMAN> backup database '/opt/software/dm8/dmdbms/data/DAMENG/dm.ini'
backup database '/opt/software/dm8/dmdbms/data/DAMENG/dm.ini'
file dm.key not found, use default license!
Read ini warning, default backup path [/opt/software/dm8/dmdbms/data/DAMENG/bak] does not exist. 
Database mode = 0, oguid = 0
Normal of FAST
Normal of DEFAULT
Normal of RECYCLE
Normal of KEEP
Normal of ROLL
EP[0]'s cur_lsn[58776], file_lsn[58776]
Processing backupset /opt/software/dm8/dmdbms/data/DAMENG/bak/DB_DAMENG_FULL_20230518_203215_182684
[Percent:100.00%][Speed:0.00M/s][Cost:00:00:02][Remaining:00:00:00]                                 
backup successfully!
time used: 00:00:03.566

## 从输出信息可以看到备份集位置为：/opt/software/dm8/dmdbms/data/DAMENG/bak/DB_DAMENG_FULL_20230518_203215_182684

二、删除system.dbf

# 备份system.dbf文件
[dmdba@alldb /opt/software/dm8/dmdbms/data/DAMENG]$ cp SYSTEM.DBF SYSTEM.DBF.bak
# 删除文件
[dmdba@alldb /opt/software/dm8/dmdbms/data/DAMENG]$ rm -f SYSTEM.DBF

三、恢复

# 尝试启动失败
[dmdba@alldb /opt/software/dm8/dmdbms/data/DAMENG]$ DmServiceDMSERVER start
Starting DmServiceDMSERVER:                                [ FAILED ]

# 恢复全备份到指定目录
RMAN> restore database to '/home/dmdba/bak' from backupset '/opt/software/dm8/dmdbms/data/DAMENG/bak/DB_DAMENG_FULL_20230518_203215_182684';
restore database to '/home/dmdba/bak' from backupset '/opt/software/dm8/dmdbms/data/DAMENG/bak/DB_DAMENG_FULL_20230518_203215_182684';
chattr: No such file or directory while trying to stat /home/dmdba/bak/dm.ctl
Normal of FAST
Normal of DEFAULT
Normal of RECYCLE
Normal of KEEP
Normal of ROLL
[Percent:100.00%][Speed:0.00M/s][Cost:00:00:02][Remaining:00:00:00]                                 
restore successfully.
time used: 00:00:03.034
# 然后将恢复的system.dbf文件拷贝到原数据目录下
[dmdba@alldb /opt/software/dm8/dmdbms/data/DAMENG]$ cp /home/dmdba/bak/SYSTEM.DBF .
# 再次还原
RMAN> restore database '/opt/software/dm8/dmdbms/data/DAMENG/dm.ini' from backupset '/opt/software/dm8/dmdbms/data/DAMENG/bak/DB_DAMENG_FULL_20230518_203215_182684';
restore database '/opt/software/dm8/dmdbms/data/DAMENG/dm.ini' from backupset '/opt/software/dm8/dmdbms/data/DAMENG/bak/DB_DAMENG_FULL_20230518_203215_182684';
Normal of FAST
Normal of DEFAULT
Normal of RECYCLE
Normal of KEEP
Normal of ROLL
[Percent:100.00%][Speed:0.00M/s][Cost:00:00:02][Remaining:00:00:00]                                 
restore successfully.
time used: 00:00:02.957

# 启动数据库，成功
[dmdba@alldb /opt/software/dm8/dmdbms/data/DAMENG]$ DmServiceDMSERVER start
Starting DmServiceDMSERVER:                                [ OK ]