今天线上数据库（版本11.2.0.1）无法建立新连接，但原有的连接不受影响，alert.log报如下错误：
opiodr aborting process unknown ospid (22997) as a result of ORA-609
但在listener.log里却显示连接已建立
03-APR-2014 16:05:44 * (CONNECT_DATA=(SERVICE_NAME=orcl2.localdomain)(CID=(PROGRAM=python@lx151)(HOST=lx151)(USER=gl))) * (ADDRESS=(PROTOCOL=tcp)(HOST=10.10.100.151)(PORT=52903)) *establish * orcl2.localdomain * 0
在sqlnet.log里报12537错误
Fatal NI connect error 12537, connecting to:
(LOCAL=NO)
VERSION INFORMATION:
TNS for Linux: Version 11.2.0.1.0 – Production
Oracle Bequeath NT Protocol Adapter for Linux: Version 11.2.0.1.0 – Production
TCP/IP NT Protocol Adapter for Linux: Version 11.2.0.1.0 – Production
Time: 03-APR-2014 15:24:30
Tracing not turned on.
Tns error struct:
ns main err code: 12537
TNS-12537: TNS:connection closed
ns secondary err code: 12560
nt main err code: 0
nt secondary err code: 0
当用lsnrctl status查看监听器状态时，卡住
通过查询官方文档，知道这是个bug，后来根据网上搜索的解决办法，链接：https://forums.oracle.com/forums/thread.jspa?messageID=4489745
删除主机文件/etc/resolv.conf，果然oracle账号恢复了，具体原因不清楚，这只是一个临时的解决办法，要想彻底解决，应该要升级。