系统管理命令
ps aux 查看所有详细后台的进程
操作系统：管理硬件软件资源的应用程序。
进程：有资格从操作系统申请资源。
守护进程：在后台运行的进程，没有终端控制的进程，反之为 非守候进程。
[zyj@localhost home]$ tail -f 1.txt dfdfsdfsf [zyj@localhost ~]$ ps aux | grep tail zyj 3157 0.0 0.0 100964 608 pts/2 S+ 09:54 0:00 tail -f 1.txt zyj 3161 0.0 0.0 103304 744 pts/1 S+ 09:54 0:00 grep tail
ps ：命令查看系统进程的详细状况；
-a ：显示终端上所有进程，包括其他用户的进程
-u：显示进程的详细状态
-x：显示没有控制终端的进程
-w：显示加宽，以便显示更多信息
-r：只显示正在运行的进程
[zyj@localhost home]$ ps au USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND root 2483 0.0 0.0 4068 544 tty2 Ss+ 09:43 0:00 /sbin/mingetty /dev/tty2 root 2485 0.0 0.0 4068 540 tty3 Ss+ 09:43 0:00 /sbin/mingetty /dev/tty3 root 2487 0.0 0.0 4068 540 tty4 Ss+ 09:43 0:00 /sbin/mingetty /dev/tty4 root 2489 0.0 0.0 4068 544 tty5 Ss+ 09:43 0:00 /sbin/mingetty /dev/tty5 root 2491 0.0 0.0 4068 540 tty6 Ss+ 09:43 0:00 /sbin/mingetty /dev/tty6 root 2513 0.5 2.8 176352 29116 tty1 Ss+ 09:43 0:04 /usr/bin/Xorg :0 -br -verbose -audit 4 -auth /var/run/gdm/auth-fo zyj 2928 0.0 0.1 108336 1684 pts/0 Ss+ 09:45 0:00 /bin/bash zyj 2949 0.0 0.1 108364 1812 pts/1 Ss+ 09:45 0:00 -bash zyj 3130 0.0 0.1 108364 1840 pts/2 Ss 09:53 0:00 -bash zyj 3219 0.0 0.1 110232 1068 pts/2 R+ 09:57 0:00 ps au
top：监控操作系统的运行情况，非守护进程，由终端控制，按q退出。
[zyj@localhost ~]$ top top - 09:59:34 up 16 min, 4 users, load average: 0.27, 0.17, 0.11 Tasks: 153 total, 1 running, 152 sleeping, 0 stopped, 0 zombie Cpu(s): 0.3%us, 0.7%sy, 0.0%ni, 97.0%id, 2.0%wa, 0.0%hi, 0.0%si, 0.0%st Mem: 1004112k total, 907020k used, 97092k free, 8272k buffers Swap: 2031612k total, 8k used, 2031604k free, 607472k cached PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 24 root 20 0 0 0 0 S 0.3 0.0 0:00.27 ata_sff/0 2948 zyj 20 0 99.7m 1856 860 S 0.3 0.2 0:00.09 sshd 3259 zyj 20 0 15036 1280 948 R 0.3 0.1 0:00.14 top 1 root 20 0 19352 1416 1096 S 0.0 0.1 0:01.98 init 2 root 20 0 0 0 0 S 0.0 0.0 0:00.00 kthreadd 3 root RT 0 0 0 0 S 0.0 0.0 0:00.00 migration/0 4 root 20 0 0 0 0 S 0.0 0.0 0:00.04 ksoftirqd/0 5 root RT 0 0 0 0 S 0.0 0.0 0:00.00 stopper/0 6 root RT 0 0 0 0 S 0.0 0.0 0:00.01 watchdog/0
kill：杀死一个进程。
[zyj@localhost home]$ tail -f 1.txt dfdfsdfsf [zyj@localhost home]$ ps aux | grep tail zyj 3316 0.0 0.0 100964 608 pts/1 S+ 10:01 0:00 tail -f 1.txt zyj 3324 0.0 0.0 103304 744 pts/2 S+ 10:02 0:00 grep tail [zyj@localhost home]$ kill -9 3316 [zyj@localhost home]$ tail -f 1.txt dfdfsdfsf Killed [zyj@localhost home]$
[zyj@localhost home]$ tail -f 1.txt dfdfsdfsf [zyj@localhost home]$ ps aux | grep tail zyj 3361 0.0 0.0 100964 608 pts/1 S+ 10:04 0:00 tail -f 1.txt zyj 3363 0.0 0.0 103304 748 pts/2 S+ 10:04 0:00 grep tail [zyj@localhost home]$ killall tail [zyj@localhost home]$ ps aux | grep tail zyj 3372 0.0 0.0 103304 748 pts/2 S+ 10:04 0:00 grep tail
系统关机重启命令：
reboot、shutdown、init
查看磁盘相关命令
df：查看磁盘分区及空间大小；任何设备使用需要挂载。
[zyj@localhost home]$ df Filesystem 1K-blocks Used Available Use% Mounted on /dev/sda2 18208184 3243892 14032708 19% / tmpfs 502056 80 501976 1% /dev/shm /dev/sda1 289293 35725 238208 14% /boot
增加一个磁盘：分区、挂载、格式化。
先在虚拟机上增加一个磁盘；
[root@localhost ~]# fdisk -l //查看磁盘信息 Disk /dev/sda: 21.5 GB, 21474836480 bytes 255 heads, 63 sectors/track, 2610 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x00093a1f Device Boot Start End Blocks Id System /dev/sda1 * 1 39 307200 83 Linux Partition 1 does not end on cylinder boundary. /dev/sda2 39 2358 18631680 83 Linux /dev/sda3 2358 2611 2031616 82 Linux swap / Solaris [root@localhost ~]# [root@localhost ~]# init 6 //关机重启后识别刚才添加的磁盘，冷启动，关电重启。
[root@localhost dev]# ls sd* sda sda1 sda2 sda3 sdb [root@localhost dev]# fdisk /dev/sdb //创建分区 Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel Building a new DOS disklabel with disk identifier 0x0c4df6a2. Changes will remain in memory only, until you decide to write them. After that, of course, the previous content won't be recoverable. Warning: invalid flag 0x0000 of partition table 4 will be corrected by w(rite) WARNING: DOS-compatible mode is deprecated. It's strongly recommended to switch off the mode (command 'c') and change display units to sectors (command 'u'). Command (m for help): m Command action a toggle a bootable flag b edit bsd disklabel c toggle the dos compatibility flag d delete a partition l list known partition types m print this menu n add a new partition o create a new empty DOS partition table p print the partition table q quit without saving changes s create a new empty Sun disklabel t change a partition's system id u change display/entry units v verify the partition table w write table to disk and exit x extra functionality (experts only) Command (m for help): n Command action e extended p primary partition (1-4) p Partition number (1-4): 1 First cylinder (1-652, default 1): Using default value 1 Last cylinder, +cylinders or +size{K,M,G} (1-652, default 652): 326 Command (m for help): n Command action e extended p primary partition (1-4) e Partition number (1-4): 2 First cylinder (327-652, default 327): Using default value 327 Last cylinder, +cylinders or +size{K,M,G} (327-652, default 652): Using default value 652 Command (m for help): m Command action a toggle a bootable flag b edit bsd disklabel c toggle the dos compatibility flag d delete a partition l list known partition types m print this menu n add a new partition o create a new empty DOS partition table p print the partition table q quit without saving changes s create a new empty Sun disklabel t change a partition's system id u change display/entry units v verify the partition table w write table to disk and exit x extra functionality (experts only) Command (m for help): w The partition table has been altered! Calling ioctl() to re-read partition table. Syncing disks. [root@localhost dev]# [root@localhost dev]# fdisk -l Disk /dev/sda: 21.5 GB, 21474836480 bytes 255 heads, 63 sectors/track, 2610 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x00093a1f Device Boot Start End Blocks Id System /dev/sda1 * 1 39 307200 83 Linux Partition 1 does not end on cylinder boundary. /dev/sda2 39 2358 18631680 83 Linux /dev/sda3 2358 2611 2031616 82 Linux swap / Solaris Disk /dev/sdb: 5368 MB, 5368709120 bytes 255 heads, 63 sectors/track, 652 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x0c4df6a2 Device Boot Start End Blocks Id System /dev/sdb1 1 326 2618563+ 83 Linux /dev/sdb2 327 652 2618595 5 Extended [root@localhost dev]# mkfs.ext3 /dev/sdb1 //格式化分区 mke2fs 1.41.12 (17-May-2010) Filesystem label= OS type: Linux Block size=4096 (log=2) Fragment size=4096 (log=2) Stride=0 blocks, Stripe width=0 blocks 163840 inodes, 654640 blocks 32732 blocks (5.00%) reserved for the super user First data block=0 Maximum filesystem blocks=671088640 20 block groups 32768 blocks per group, 32768 fragments per group 8192 inodes per group Superblock backups stored on blocks: 32768, 98304, 163840, 229376, 294912 Writing inode tables: done Creating journal (16384 blocks): done Writing superblocks and filesystem accounting information: done This filesystem will be automatically checked every 25 mounts or 180 days, whichever comes first. Use tune2fs -c or -i to override. [root@localhost dev]# mkdir /opt/my_disk [root@localhost dev]# [root@localhost dev]# mount /dev/sdb1 /opt/my_disk/ //挂载分区 [root@localhost dev]# cd /opt/my_disk/ [root@localhost my_disk]# ll total 16 drwx------. 2 root root 16384 Apr 27 10:05 lost+found
du：检测目录所占磁盘空间，用于统计目录或文件所占磁盘空间的大小，执行结果与df类似，du更侧重于与磁盘的使用状况。
du -a 递归显示指定目录中各文件和子目录文件占用的数据块；
du -s 显示指定文件或目录占用的数据块
du -b 以字节为单位显示磁盘占用情况
du -l 计算所有文件大小，对硬连接文件计算多次
[root@localhost home]# cd x [root@localhost x]# ll total 104 -rw-----w-. 1 root root 3361 Apr 15 05:27 anaconda-ks.cfg -rw-r--rw-. 1 root root 41915 Apr 15 05:27 install.log -rw-r--rw-. 1 root root 9154 Apr 15 05:27 install.log.syslog -rw-r--rw-. 1 root root 41915 Apr 15 05:25 my.log [root@localhost x]# du -a 44 ./my.log 12 ./install.log.syslog 4 ./anaconda-ks.cfg 44 ./install.log 108 . [root@localhost x]# du -ab 41915 ./my.log 9154 ./install.log.syslog 3361 ./anaconda-ks.cfg 41915 ./install.log 100441 . [root@localhost x]# du -s my.log 44 my.log [root@localhost x]# du -al | sort -n 4 ./anaconda-ks.cfg 12 ./install.log.syslog 44 ./install.log 44 ./my.log 108 . [root@localhost x]#
ifconfig：查看网络配置情况，重启网络接口。
[root@localhost ~]# ifconfig eth0 Link encap:Ethernet HWaddr 00:0C:29:6F:58:E8 inet addr:192.168.166.128 Bcast:192.168.166.255 Mask:255.255.255.0 inet6 addr: fe80::20c:29ff:fe6f:58e8/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:1668 errors:0 dropped:0 overruns:0 frame:0 TX packets:1606 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:154503 (150.8 KiB) TX bytes:1121694 (1.0 MiB) lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 inet6 addr: ::1/128 Scope:Host UP LOOPBACK RUNNING MTU:65536 Metric:1 RX packets:46 errors:0 dropped:0 overruns:0 frame:0 TX packets:46 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:2340 (2.2 KiB) TX bytes:2340 (2.2 KiB)
[root@localhost ~]# ifconfig eth0 up //精准方式开启关闭对应接口
[root@localhost ~]# ifconfig eth0 down
[root@localhost ~]# service network restart //启动所有网络接口
ping：测试网络连通性
[root@localhost ~]# ping -c1 www.baidu.com PING www.a.shifen.com (180.97.33.108) 56(84) bytes of data. 64 bytes from www.baidu.com (180.97.33.108): icmp_seq=1 ttl=128 time=39.4 ms --- www.a.shifen.com ping statistics --- 1 packets transmitted, 1 received, 0% packet loss, time 47ms rtt min/avg/max/mdev = 39.490/39.490/39.490/0.000 ms
默认会ping无限次
[root@localhost ~]# ping www.baidu.com PING www.a.shifen.com (180.97.33.107) 56(84) bytes of data. 64 bytes from 180.97.33.107: icmp_seq=1 ttl=128 time=36.9 ms 64 bytes from 180.97.33.107: icmp_seq=2 ttl=128 time=37.9 ms 64 bytes from 180.97.33.107: icmp_seq=3 ttl=128 time=36.9 ms 64 bytes from 180.97.33.107: icmp_seq=4 ttl=128 time=42.4 ms
tar 解压压缩命令：
[root@localhost home]# tar -zcvf x.tar.gz x/ //压缩x目录 x/ x/my.log x/install.log.syslog x/anaconda-ks.cfg x/install.log [root@localhost home]# [root@localhost home]# ll total 44 -rwxrwxrwx. 1 root root 10 Apr 25 11:05 1.txt -rwxrwxrwx. 1 zyj zyj 86 Apr 15 09:23 hello.txt drwx------. 4 sl sl 4096 Apr 25 10:16 sl drwxr-xrwx. 2 root root 4096 Apr 15 07:00 x -rw-r--r--. 1 root root 21997 Apr 26 10:55 x.tar.gz drwx------. 24 zyj zyj 4096 Apr 26 10:24 zyj [root@localhost home]# [root@localhost home]# mv x.tar.gz /opt/ [root@localhost home]# cd /opt/ [root@localhost opt]# ll total 32 drwxr-xr-x. 2 root root 4096 Mar 26 2015 rh drwxr-xr-x. 2 root root 4096 Apr 15 05:30 x -rw-r--r--. 1 root root 21997 Apr 26 10:55 x.tar.gz [root@localhost opt]# [root@localhost opt]# [root@localhost opt]# tar -zxvf x.tar.gz //解压缩 x/ x/my.log x/install.log.syslog x/anaconda-ks.cfg x/install.log [root@localhost opt]# ll total 32 drwxr-xr-x. 2 root root 4096 Mar 26 2015 rh drwxr-xrwx. 2 root root 4096 Apr 15 07:00 x -rw-r--r--. 1 root root 21997 Apr 26 10:55 x.tar.gz
netstat 查看网络情况
[root@localhost ~]# netstat -ntpl Active Internet connections (only servers) Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN 2254/sshd tcp 0 0 127.0.0.1:631 0.0.0.0:* LISTEN 2095/cupsd tcp 0 0 127.0.0.1:25 0.0.0.0:* LISTEN 2392/master tcp 0 0 :::22 :::* LISTEN 2254/sshd tcp 0 0 ::1:631 :::* LISTEN 2095/cupsd tcp 0 0 ::1:25 :::* LISTEN 2392/master