1 [root@localhost ~]# umount /mnt 2 umount.nfs: /mnt: device is busy 3 umount.nfs: /mnt: device is busy
问题原因：有进程在占用，一般原因是有其他人同时登陆并在操作使用
解决方法：可以通过
#fuser -m -v /mnt/nfs
找到进程号（带有用户、进程号、权限、命令），无用的情况下，可通过
#kill -9 进程号
关闭进程，再次执行umount即可
'''解除磁盘挂载'''
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'''Oracle监听启动失败'''
$ lsnrctl start LSNRCTL for Linux: Version 11.2.0.3.0 - Production on ************ Copyright (c) 1991, 2011, Oracle. All rights reserved. Starting /dba/oracle/product/11.2.0/db_1/bin/tnslsnr: please wait... TNSLSNR for Linux: Version 11.2.0.3.0 - Production System parameter file is /dba/oracle/product/11.2.0/db_1/network/admin/listener.ora Log messages written to /dba/oracle/diag/tnslsnr/ol6-single/listener/alert/log.xml Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=ol6-single)(PORT=1521))) Error listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC1521))) TNS-12555: TNS:permission denied TNS-12560: TNS:protocol adapter error TNS-00525: Insufficient privilege for operation Linux Error: 1: Operation not permitted
问题原因：文件没有操作读取权限，一般Oracle安装都是专门的用户，这一块不存在权限不足的问题，记得以前看到过/var/tmp目录下有个隐藏文件夹.oracle，查看是否是因为用户及用户组归属问题
解决方法：
ls -lrtd /var/tmp/.oracle
修改文件归属用户
chown -R oracle:dba /var/tmp/.oracle
重新启动
'''Oracle监听启动失败'''
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'''批量修改文件夹下所有文件中的某一个字符串'''
将/xiugai_mulu目录下的所有文件中xiugai_before修改为xiugai_afer
sed -i "s/xiugai_before/xiugai_afer/g" `grep xiugai_before -rl /xiugai_mulu`
-i 表示inplace edit，就地修改文件
-r 表示搜索子目录
-l 表示输出匹配的文件名