1、使用达梦数据库控制管理工具备份数据库实例后，发现无法启动数据库实例服务
[dmdba@redhat init.d]$ service DmServiceDMSERVER1 start
Starting DmServiceDMSERVER1: [ FAILED ]
file dm.key not found, use default license!
version info: develop
Use normal os_malloc instead of HugeTLB
Use normal os_malloc instead of HugeTLB
DM Database Server x64 V8 1-1-45-19.11.21-116030-ENT startup…
Database mode = 0, oguid = 0
License will expire on 2020-11-21
Instance DMSERVER1 startup failed, execute ‘recover database … update db_magic’ in dmrman.

2、因为DM8比DM7多了更新db_magic这个步骤，所以按照下面的方法更新db_magic

[dmdba@redhat bin]$ ./dmrman
dmrman V8
RMAN> recover database ‘/opt/dmdbms/data/DAMENG1/dm.ini’ update db_magic
recover database ‘/opt/dmdbms/data/DAMENG1/dm.ini’ update db_magic
file dm.key not found, use default license!
Database mode = 0, oguid = 0
EP[0]'s cur_lsn[125265]
EP[0]'s apply_lsn[125265] >= end_lsn[125265]
recover successfully!
time used: 00:00:01.064
RMAN> exit
time used: 0.017(ms)
3、重新启动数据库实例服务
[dmdba@redhat init.d]$ service DmServiceDMSERVER1 start
Starting DmServiceDMSERVER1: [ OK ]
[dmdba@redhat init.d]$ service DmServiceDMSERVER1 status
DmServiceDMSERVER1 (pid 5782) is running…