在做dg库主备切换的时候，dg库强制执行了切换命令，导致主库rac的主节点现在起不来，一直报这个错

SQL> startup mount;

ORACLE instance started.

Total System Global Area 2.0176E+10 bytes
Fixed Size 2261928 bytes
Variable Size 4697623640 bytes
Database Buffers 1.5435E+10 bytes
Redo Buffers 41463808 bytes
ORA-01105: mount is incompatible with mounts by other instances
ORA-01154: database busy. Open, close, mount, and dismount not allowed now