由于机房突然掉电，发现有一台开发用数据库无法正常启动，看来是文件损坏了，没有备份 。

SQL> startup
ORACLE instance started.

Total System Global Area 901775360 bytes
Fixed Size 2024944 bytes
Variable Size 155191824 bytes
Database Buffers 742391808 bytes
Redo Buffers 2166784 bytes
Database mounted.
ORA-01115: IO error reading block from file 3 (block # 28760)
ORA-01110: data file 3: '/u02/oradata/devdb/sysaux01.dbf'
ORA-27072: File I/O error
Linux-x86_64 Error: 2: No such file or directory
Additional information: 4
Additional information: 28758
Additional information: 8192
ORA-01115: IO error reading block from file 3 (block # 28759)
ORA-01110: data file 3: '/u02/oradata/devdb/sysaux01.dbf'
ORA-27072: File I/O error
Linux-x86_64 Error: 2: No such file or directory
Additional information: 4
Additional information: 28758
Additional information: 8192

辅助表空间坏了，看来是硬盘了问题了，文档上说辅助表空间不可用时，oracle的核心功能是可用的，于是将破坏的文件去掉试试。
SQL> startup mount
ORACLE instance started.

Total System Global Area 901775360 bytes
Fixed Size 2024944 bytes
Variable Size 155191824 bytes
Database Buffers 742391808 bytes
Redo Buffers 2166784 bytes
Database mounted.
SQL> alter database datafile '/u02/oradata/devdb/sysaux01.dbf' offline drop;

Database altered.

SQL> alter database open;

Database altered.

果然可以，试试一般功能是可用的，但全文索引，exp users等是不可用的，还好exp tables是可用的，可以重新装一台，将数据导过去。