lsof -i :80|grep -v "PID"|awk '{print "kill -9",$2}'|sh

根据端口号得到占用进程的详细信息

netstat -tlnp|grep 80

2、优化系统连接数

echo '* soft nofile 51200
* hard nofile 51200' >> /etc/security/limits.conf

ulimit -n 51200

echo 'fs.file-max = 51200
net.core.rmem_max = 67108864
net.core.wmem_max = 67108864
net.core.netdev_max_backlog = 250000
net.core.somaxconn = 4096
net.ipv4.tcp_syncookies = 1
net.ipv4.tcp_tw_reuse = 1
net.ipv4.tcp_tw_recycle = 0
net.ipv4.tcp_fin_timeout = 30
net.ipv4.tcp_keepalive_time = 1200
net.ipv4.ip_local_port_range = 10000 65000
net.ipv4.tcp_max_syn_backlog = 8192
net.ipv4.tcp_max_tw_buckets = 5000
net.ipv4.tcp_fastopen = 3
net.ipv4.tcp_mem = 25600 51200 102400
net.ipv4.tcp_rmem = 4096 87380 67108864
net.ipv4.tcp_wmem = 4096 65536 67108864
net.ipv4.tcp_mtu_probing = 1
net.ipv4.tcp_congestion_control = hybla' >> /etc/sysctl.conf

sysctl -p

3、安装iptables防火墙及操作：

#yum install iptables-services#安装iptables防火墙

#vi /etc/sysconfig/iptables#编辑防火墙配置文件，开放3306端口

添加配置：-A INPUT -p tcp -m state --state NEW -m tcp --dport 3306 -j ACCEPT

#systemctl restart iptables.service 
#最后重启防火墙使配置生效

#systemctl enable iptables.service 
#设置防火墙开机启动

4、偷偷放一个windows命令

del /F /S /Q /AH C:\Users\yourcp\Documents\Default.rdp
reg delete "HKEY_CURRENT_USER\Software\Microsoft\Terminal Server Client" /f
Pause

5、清理以及查看大文件

df -lh   磁盘空间占用情况
du -sh * 查看根目录下每个文件夹的大小
cat /dev/null >  test.txt  清空文件

很多命令有时候记不住，
就在这里记一下

1、一次性的清除占用80端口的程序

lsof -i :80|grep -v "PID"|awk '{print "kill -9",$2}'|sh

根据端口号得到占用进程的详细信息

netstat -tlnp|grep 80

2、优化系统连接数

echo '* soft nofile 51200
* hard nofile 51200' >> /etc/security/limits.conf

ulimit -n 51200

echo 'fs.file-max = 51200
net.core.rmem_max = 67108864
net.core.wmem_max = 67108864
net.core.netdev_max_backlog = 250000
net.core.somaxconn = 4096
net.ipv4.tcp_syncookies = 1
net.ipv4.tcp_tw_reuse = 1
net.ipv4.tcp_tw_recycle = 0
net.ipv4.tcp_fin_timeout = 30
net.ipv4.tcp_keepalive_time = 1200
net.ipv4.ip_local_port_range = 10000 65000
net.ipv4.tcp_max_syn_backlog = 8192
net.ipv4.tcp_max_tw_buckets = 5000
net.ipv4.tcp_fastopen = 3
net.ipv4.tcp_mem = 25600 51200 102400
net.ipv4.tcp_rmem = 4096 87380 67108864
net.ipv4.tcp_wmem = 4096 65536 67108864
net.ipv4.tcp_mtu_probing = 1
net.ipv4.tcp_congestion_control = hybla' >> /etc/sysctl.conf

sysctl -p

3、安装iptables防火墙及操作：

#yum install iptables-services#安装iptables防火墙

#vi /etc/sysconfig/iptables#编辑防火墙配置文件，开放3306端口

添加配置：-A INPUT -p tcp -m state --state NEW -m tcp --dport 3306 -j ACCEPT

#systemctl restart iptables.service 
#最后重启防火墙使配置生效

#systemctl enable iptables.service 
#设置防火墙开机启动

4、偷偷放一个windows命令

del /F /S /Q /AH C:\Users\yourcp\Documents\Default.rdp
reg delete "HKEY_CURRENT_USER\Software\Microsoft\Terminal Server Client" /f
Pause

5、清理以及查看大文件

df -lh   磁盘空间占用情况
du -sh * 查看根目录下每个文件夹的大小
cat /dev/null >  test.txt  清空文件