Linux系统中，启动oracle监听的时候报如下错误：

[oracle@centos ~]$ lsnrctl start

LSNRCTL for Linux: Version 10.2.0.1.0 - Production on 17-APR-2010 00:25:22

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

Starting /u01/app/oracle/product/10.2.0/db_1/bin/tnslsnr: please wait...

TNS-12537: TNS:connection closed

TNS-12560: TNS:protocol adapter error

TNS-00507: Connection closed

Linux Error: 29: Illegal seek 

经过检查，发现hosts文件，内容如下：

[root@centos ~]# cat /etc/hosts

# Do not remove the following line, or various programs

# that require network functionality will fail.

::1 localhost.localdomain localhost

192.168.19.219 centos 

缺少了 127.0.0.1 localhost行，加上这行后，如下所示，监听就可以正常启动了。

[root@centos ~]# cat /etc/hosts

# Do not remove the following line, or various programs

# that require network functionality will fail.

::1 localhost.localdomain localhost

127.0.0.1 localhost

192.168.19.219 centos