类 Unix 系统下的一些常用命令和用法。
实用命令
fuser
查看文件被谁占用。
fuser -u .linux.md.swp
id
查看当前用户、组 id。
lsof
查看打开的文件列表。
An open file may be a regular file, a directory, a block special file, a character special file, an executing text reference, a library, a stream or a network file (Internet socket, NFS file or UNIX domain socket.) A specific file or all the files in a file system may be selected by path.
查看网络相关的文件占用
lsof -i
查看端口占用
lsof -i tcp:5037
查看某个文件被谁占用
lsof .linux.md.swp
查看某个用户占用的文件信息
lsof -u mazhuang
-u 后面可以跟 uid 或 login name。
查看某个程序占用的文件信息
lsof -c Vim
注意程序名区分大小写。
安全知识
ubunbu下使用 fail2ban自动封禁攻击IP
可自动读取var/log/auth.log下的攻击者IP，使用iptables进行封禁
pam-servicesshd-ignoring-max-retries
While the other answers are correct in elimiating the error message you got, consider that this error message may just be a symptom of another underlying problem.
You get these messages because there are many failing login attempts via ssh on your system. There may be someone trying to brute-force into your box (was the case when I got the same messages on my system). Read your var/log/auth.log for research…
If this is the case, you shoud consider installing a tool like ‘fail2ban’ (sudo apt-get install fail2ban on Ubuntu). It automatically reads the log files of your system, searches for multiple failed login attempts and blocks the malicious clients for a configurable time via iptables…