oracle xe启动监听失败

环境:oracle-xe-univ-10.2.0.1-1.0.i386
一、情况1，启动监听失败
现象:安装完成，启动监听报错
#lsnrctl start
LSNRCTL for Linux: Version 11.1.0.6.0 - Production on 28-11月-2009 18:55:00

Copyright (c) 1991, 2007, Oracle.  All rights reserved.

启动/home/oracle/product/11g/db_1/bin/tnslsnr: 请稍候...

TNSLSNR for Linux: Version 11.1.0.6.0 - Production
系统参数文件为/home/oracle/product/11g/db_1/network/admin/listener.ora
写入/home/oracle/diag/tnslsnr/Web2/listener/alert/log.xml的日志信息
监听: (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=Web2.site)(PORT=1521)))
监听该对象时出错: (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC1521)))
TNS-12555: TNS: 权限被拒绝
TNS-12560: TNS: 协议适配器错误
  TNS-00525: 无足够权限以执行操作
   Linux Error: 1: Operation not permitted

监听程序未能启动。请参阅上面的错误消息..

/tmp/.oracle的权限
/var/tmp/.oracle的权限

oracle应该有这些目录的权限，用oinstall
chown -R  oracle:oinstall /tmp/.oracle
chown -R  oracle:oinstall /var/tmp/.oracle

情况二、由于hosts文件设置问题，导致启动失败
查看启动日志
/usr/lib/oracle/xe/app/oracle/product/10.2.0/server/network/log/listener.log


TNSLSNR for Linux: Version 10.2.0.1.0 - Production on 19-DEC-2012 22:26:41

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

System parameter file is /usr/lib/oracle/xe/app/oracle/product/10.2.0/server/network/admin/listener.ora
Log messages written to /usr/lib/oracle/xe/app/oracle/product/10.2.0/server/network/log/listener.log
Trace information written to /usr/lib/oracle/xe/app/oracle/product/10.2.0/server/network/trace/listener.trc
Trace level is currently 0

Started with pid=10273
Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC_FOR_XE)))
Error listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=mypc)(PORT=1521)))
TNS-12545: Connect failed because target host or object does not exist
TNS-12560: TNS:protocol adapter error
  TNS-00515: Connect failed because target host or object does not exist
   Linux Error: 11: Resource temporarily unavailable
No longer listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC_FOR_XE)))

推断因该是 通过mypc这个hostname无法找到机器
查看/etc/hosts文件如下
127.0.0.1               localhost.localdomain localhost
::1             localhost6.localdomain6 localhost6
果然有问题，在hosts文件中添加如下一行即可
192.168.0.5 mypc