[oracle@chen etc]$ lsnrctl status

LSNRCTL for Linux: Version 10.2.0.1.0 - Production on 19-APR-2012 09:37:45

Copyright (c) 1991, 2005, Oracle.  All rights reserved.

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC1)))

TNS-12541: TNS:no listener

TNS-12560: TNS:protocol adapter error

TNS-00511: No listener

 Linux Error: 111: Connection refused

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=chen.yun)(PORT=1521)))

TNS-12541: TNS:no listener

 TNS-12560: TNS:protocol adapter error

  TNS-00511: No listener

   Linux Error: 111: Connection refused

出现这种情况的原因：etc/hosts下删除了 localhosts的原因

解决方案：vi  /etc/hosts

添加用户 127.0.0.1       localhost.localdomain   localhost  保存退出

再次运行即可