今天通过rman 连接oracle 发现一台节点，提示没有挂载，很是突兀，完成没搞过这破玩意，在网上查了很多资料，让从别一节点上备份，然后在这一台上进行恢复；但是我查了一下备份的内容，这台连不上的上面都有，而且文件也是一致的，所以我直接做了挂载动作
第一步：从DB2 上获取到DBID
[oracle@DB2 ~]$ rman
Recovery Manager: Release 11.2.0.4.0 - Production on Wed Jul 5 18:28:39 2023
Copyright (c) 1982, 2011, Oracle and/or its affiliates. All rights reserved.
RMAN> connect target /
connected to target database: GENDB (DBID=27951032)
第二步：把DB2上的DBID 设置到DB1上，并进行数据库挂载，并退出
[oracle@DB1 ~]$ rman
Recovery Manager: Release 11.2.0.4.0 - Production on Wed Jul 5 18:27:55 2023
Copyright (c) 1982, 2011, Oracle and/or its affiliates. All rights reserved.
RMAN> connect target /
connected to target database: GENDB (not mounted)
RMAN> set DBID=27951032 // 在好的一台上取DBID
executing command: SET DBID
RMAN> alter database mount;
using target database control file instead of recovery catalog
database mounted
RMAN> exit
第三步：退出后，重新连接，会提示数据库有打开 not open， 重新打开数据库
[oracle@DB1 ~]$ rman
Recovery Manager: Release 11.2.0.4.0 - Production on Wed Jul 5 18:31:05 2023
Copyright (c) 1982, 2011, Oracle and/or its affiliates. All rights reserved.
RMAN> connect target /
connected to target database: GENDB (DBID=27951032, not open)
RMAN> alter database open;
using target database control file instead of recovery catalog
database opened
RMAN> exit
第四步：测试挂载完成， 查询备份设置，一切正常。。。
[oracle@DB1 ~]$ rman
Recovery Manager: Release 11.2.0.4.0 - Production on Wed Jul 5 18:37:39 2023
Copyright (c) 1982, 2011, Oracle and/or its affiliates. All rights reserved.
RMAN> connect target /
connected to target database: GENDB (DBID=27951032) 完成挂载
RMAN> list backupset;
using target database control file instead of recovery catalog
List of Backup Sets
===================
BS Key Type LV Size Device Type Elapsed Time Completion Time
------- ---- -- ---------- ----------- ------------ ---------------
6088 Incr 1 1.50G DISK 00:09:41 04-JUL-23
BP Key: 6088 Status: AVAILABLE Compressed: NO Tag: TAG20230704T220004
Piece Name: /home/oracle/ora_backupset/backupset/20230704/5f20eqn7
List of Datafiles in backup set 6088
File LV Type Ckp SCN Ckp Time Name