做全備測試的時候碰到下面情況，此時數據庫服務已經關閉。
[dmdba@localhost ~]$ dmrman
dmrman V7.6.0.197-Build(2019.09.12-112648)ENT
RMAN> backup database '/dm7/data/DM01/dm.ini';
backup database '/dm7/data/DM01/dm.ini';
file dm.key not found, use default license!
checking if the database under system path [/dm7/data/DM01] is running...[4].
checking if the database under system path [/dm7/data/DM01] is running...[3].
checking if the database under system path [/dm7/data/DM01] is running...[2].
checking if the database under system path [/dm7/data/DM01] is running...[1].
checking if the database under system path [/dm7/data/DM01] is running...[0].
checking if the database under system path [/dm7/data/DM01] is running, write dmrman info.
EP[0] max_lsn: 59275
BACKUP DATABASE [DM01],execute......
os_pipe2_conn_server open failed, name:[/home/dmdba/DM_PIPE_DMAP_LSNR_WR], errno:2
CMD END.CODE:[-7109],DESC:[Pipe connect failure]
[-7109]:Pipe connect failure
RMAN> exit
exit
但是奇怪的是，直接cd到 dmrman的路徑下面執行，是可以成功的，可能是執行備份時沒有找到需要的文件。
[dmdba@localhost ~]$ cd /dm7/dameng/bin
[dmdba@localhost bin]$ ./dmrman
dmrman V7.6.0.197-Build(2019.09.12-112648)ENT
RMAN> backup database '/dm7/data/DM01/dm.ini';
backup database '/dm7/data/DM01/dm.ini';
file dm.key not found, use default license!
checking if the database under system path [/dm7/data/DM01] is running...[4].
checking if the database under system path [/dm7/data/DM01] is running...[3].
checking if the database under system path [/dm7/data/DM01] is running...[2].
checking if the database under system path [/dm7/data/DM01] is running...[1].
checking if the database under system path [/dm7/data/DM01] is running...[0].
checking if the database under system path [/dm7/data/DM01] is running, write dmrman info.
EP[0] max_lsn: 59275
BACKUP DATABASE [DM01],execute......
CMD CHECK LSN......
BACKUP DATABASE [DM01],collect dbf......
CMD CHECK ......
DBF BACKUP SUBS......
total 1 packages processed...
total 3 packages processed...
total 4 packages processed...
DBF BACKUP MAIN......
BACKUPSET [/dm7/data/DM01/bak/DB_DM01_FULL_20191031_025308_000315] END, CODE [0]......
META GENERATING......
total 6 packages processed...
total 6 packages processed!
CMD END.CODE:[0]
backup successfully!
time used: 7030.115(ms)