在DMRMAN 中执行命令报错(DMAP服务后台正常启动)：

RMAN> BACKUP DATABASE '/dm/dmdbms/data/DAMENG/dm.ini';
BACKUP DATABASE '/dm/dmdbms/data/DAMENG/dm.ini';
checking if the database under system path [/dm/dmdbms/data/DAMENG] is running...[4].
checking if the database under system path [/dm/dmdbms/data/DAMENG] is running...[3].
checking if the database under system path [/dm/dmdbms/data/DAMENG] is running...[2].
checking if the database under system path [/dm/dmdbms/data/DAMENG] is running...[1].
checking if the database under system path [/dm/dmdbms/data/DAMENG] is running...[0].
checking if the database under system path [/dm/dmdbms/data/DAMENG] is running, write dmrman info.
EP[0] max_lsn: 155855
BACKUP DATABASE [DAMENG], execute......
os_pipe2_conn_server open failed, name:[/dm/dm_bak/DM_PIPE_DMAP_LSNR_WR], errno:2
CMD END.CODE:[-7109],DESC:[Pipe connect failure]
[-7109]:Pipe connect failure
RMAN>

解决方法:

方法(1)

必须到DM_HOME/bin 目录下执行DMRMAN， 虽然配置了环境变量可以识别到DMRMAN命令，但执行还是会报错，推测是程序执行时依赖的文件无法正确识别到，切换到$DM_HOME/bin就解决这个问题了。

[dmdba@www.zidu.cn bin]$ pwd
/dm/dmdbms/bin
[dmdba@www.zidu.cn bin]$ ./dmrman
dmrman V7.6.0.95-Build(2018.09.13-97108)ENT 
RMAN> BACKUP DATABASE '/dm/dmdbms/data/DAMENG/dm.ini' FULL BACKUPSET '/dm/dm_bak/db_full_bak_01';
BACKUP DATABASE '/dm/dmdbms/data/DAMENG/dm.ini' FULL BACKUPSET '/dm/dm_bak/db_full_bak_01';
file dm.key not found, use default license!
Global parameter value of RT_HEAP_TARGET is illegal, use min value!
checking if the database under system path [/dm/dmdbms/data/DAMENG] is running...[4].
checking if the database under system path [/dm/dmdbms/data/DAMENG] is running...[3].
checking if the database under system path [/dm/dmdbms/data/DAMENG] is running...[2].
checking if the database under system path [/dm/dmdbms/data/DAMENG] is running...[1].
checking if the database under system path [/dm/dmdbms/data/DAMENG] is running...[0].
checking if the database under system path [/dm/dmdbms/data/DAMENG] is running, write dmrman info.
EP[0] max_lsn: 116978
BACKUP DATABASE [DAMENG], execute......
CMD CHECK LSN......
BACKUP DATABASE [DAMENG], collect dbf......
CMD CHECK ......
DBF BACKUP SUBS......
total 1 packages processed...
total 3 packages processed...
total 4 packages processed...
DBF BACKUP MAIN......
BACKUPSET [/dm/dm_bak/db_full_bak_01] END, CODE [0]......
META GENERATING......
total 5 packages processed...
total 5 packages processed!
CMD END.CODE:[0]
backup successfully!
time used: 7081.941(ms)
RMAN>

方法(2)

日志报错，管道文件已存在，删除管道文件后报错os_pipe2_server open failed，排查数据写入没有权限修改权限，后报错管道连接超时
使用./dmrman use_ap=2不使用管道dmap进行还原成功。