1、rename
rename bcp.bad bcp *.bad
2、screen
Ctrl+A，然后快速按D退出screen窗口
安装screen
[root@aaa ~]# yum install screen -y
Loaded plugins: fastestmirror, langpacks
Loading mirror speeds from cached hostfile
base | 3.6 kB 00:00:00
extras | 3.4 kB 00:00:00
updates | 3.4 kB 00:00:00
(1/2): extras/7/x86_64/primary_db | 187 kB 00:00:00
(2/2): updates/7/x86_64/primary_db | 5.2 MB 00:00:02
Resolving Dependencies
--> Running transaction check
---> Package screen.x86_64 0:4.1.0-0.25.20120314git3c2946.el7 will be installed
--> Finished Dependency Resolution
Dependencies Resolved
==============================================================================================================
Package Arch Version Repository Size
==============================================================================================================
Installing:
screen x86_64 4.1.0-0.25.20120314git3c2946.el7 base 552 k
Transaction Summary
==============================================================================================================
Install 1 Package
Total download size: 552 k
Installed size: 914 k
Downloading packages:
screen-4.1.0-0.25.20120314git3c2946.el7.x86_64.rpm | 552 kB 00:00:00
Running transaction check
Running transaction test
Transaction test succeeded
Running transaction
Installing : screen-4.1.0-0.25.20120314git3c2946.el7.x86_64 1/1
Verifying : screen-4.1.0-0.25.20120314git3c2946.el7.x86_64 1/1
Installed:
screen.x86_64 0:4.1.0-0.25.20120314git3c2946.el7
Complete!查看是否安装成功
[root@aaa ~]# rpm -qa | grep screen
gnome-screenshot-3.22.0-1.el7.x86_64
screen-4.1.0-0.25.20120314git3c2946.el7.x86_643、防火墙
查看防火墙开启端口号
iptables -L -n开启端口号
firewall-cmd --permanent --add-port=8080/tcp --zone=public
firewall-cmd --reload关闭端口号
firewall-cmd --permanent --remove-port=8080/tcp --zone=public
firewall-cmd --reload4、scp
4.1 从本地复制到远程
复制文件
scp /data/1.txt [email protected]:/data/复制目录命令格式
scp -r /data/ [email protected]:/data/4.2 从远程复制到本地
scp [email protected]:/data/ /data/1.txt
scp -r [email protected]:/data/ /data/5、查看系统日志
cat /var/log/messages6、显示系统运行时间信息
uptime/w/top
w命令的第一行与uptime命令的输出是相同的
top命令的第一行与uptime命令的输出是相同的，另外几行与free命令的输出相似。
两个法则，作为判断系统负荷是否过大：
“有多少核心即为有多少负荷”法则：在多核处理中，你的系统均值不应该高于处理器核心的总数量。（尤其是第三个值，即15分钟平均系统负荷）
“核心的核心”法则：核心分布在分别几个单个物理处理中并不重要，其实两颗四核的处理器 等于 四个双核处理器 等于 八个单处理器。所以，它应该有八个处理器内核。
[root@web ~]# uptime
17:38:46 up 70 days, 8:38, 3 users, load average: 0.05, 0.06, 0.05
[root@web ~]# w
17:38:51 up 70 days, 8:39, 3 users, load average: 0.04, 0.06, 0.05
USER TTY FROM LOGIN@ IDLE JCPU PCPU WHAT
root pts/0 172.16.0.156 15:28 2:10m 0.06s 0.06s -bash
root pts/1 172.16.0.155 09:30 8:08m 0.07s 0.07s -bash
root pts/2 172.16.0.157 17:38 3.00s 0.08s 0.01s w
[root@web ~]# top
top - 17:38:21 up 70 days, 8:38, 3 users, load average: 0.07, 0.07, 0.05
Tasks: 540 total, 1 running, 539 sleeping, 0 stopped, 0 zombie
%Cpu(s): 0.1 us, 0.4 sy, 0.0 ni, 99.4 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st
KiB Mem : 29671600+total, 86688648 free, 20272104 used, 18975524+buff/cache
KiB Swap: 13421772+total, 13416320+free, 54528 used. 25605281+avail Mem
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
18771 root 20 0 162368 2560 1524 R 11.8 0.0 0:00.03 top
1 root 20 0 197228 6644 4188 S 0.0 0.0 9:41.74 systemd
2 root 20 0 0 0 0 S 0.0 0.0 0:04.37 kthreadd
3 root 20 0 0 0 0 S 0.0 0.0 0:09.69 ksoftirqd/0
5 root 0 -20 0 0 0 S 0.0 0.0 0:00.00 kworker/0:+
8 root rt 0 0 0 0 S 0.0 0.0 0:11.49 migration/0
9 root 20 0 0 0 0 S 0.0 0.0 0:00.00 rcu_bh
10 root 20 0 0 0 0 S 0.0 0.0 30:09.82 rcu_sched
11 root 0 -20 0 0 0 S 0.0 0.0 0:00.00 lru-add-dr+
12 root rt 0 0 0 0 S 0.0 0.0 0:13.36 watchdog/0
13 root rt 0 0 0 0 S 0.0 0.0 0:12.82 watchdog/1
14 root rt 0 0 0 0 S 0.0 0.0 0:11.05 migration/1
15 root 20 0 0 0 0 S 0.0 0.0 0:02.00 ksoftirqd/1
17 root 0 -20 0 0 0 S 0.0 0.0 0:00.00 kworker/1:+
18 root rt 0 0 0 0 S 0.0 0.0 0:10.93 watchdog/2
19 root rt 0 0 0 0 S 0.0 0.0 0:10.65 migration/2
20 root 20 0 0 0 0 S 0.0 0.0 0:01.10 ksoftirqd/2
22 root 0 -20 0 0 0 S 0.0 0.0 0:00.00 kworker/2:+