Several Linux commands to understand the performance profile of a Linux system

Linux systems have some basic commands that can be well used for server monitoring.

For a brief introduction, use Help to view or access relevant information.

• Network: Ifconfig,netstat
• Disk: DF
• Cpu:w
• Process: PS
• Memory: Free
• I/o:iostat

Ifconfig

Enter ifconfig and the output is:

Eth0:flags=4163<Up,broadcast,running,multicast>Mtu theinet10.144. Bayi. 226Netmask255.255.. 0Broadcast10.144.. 255Etherxx: -:3E: Geneva:Geneva: BA Txqueuelen +(Ethernet)RXPackets69775  bytes 91364566(87.1MiB)RXErrors0Dropped0Overruns0Frame0TX Packets26057  bytes 1937311(1.8MiB) TX Errors0Dropped0Overruns0Carrier0Collisions0Lo:flags= the<Up,loopback,running>Mtu65536inet127.0. 0. 1Netmask255.0. 0. 0        LoopTxqueuelen0(LocalLoopback)RXPackets286  bytes 32054(31.3KiB)RXErrors0Dropped0Overruns0Frame0TX Packets286  bytes 32054(31.3KiB) TX Errors0Dropped0Overruns0Carrier0Collisions0

The results show the number of network cards, IP address, MAC address, MTU size, network card transceiver packet.
EthX (x for 0,1,2 ...), there are several net cards, inet is the IP address, netmask is the subnet mask, broadcast is the broadcast address

Netstat

Netstat is a command to view network-related data.

ActiveInternet connections (servers and established) Proto recv-q send-q Local address Foreign address state Timertcp0      0 127.0.0.1:8005          0.0.0.0:* LISTENoff(0. $tcp0      0 0.0.0.0:8009            0.0.0.0:* LISTENoff(0. $tcp0      0 0.0.0.0:80              0.0.0.0:* LISTENoff(0. $tcp0      0 0.0.0.0:8080            0.0.0.0:* LISTENoff(0. $tcp0      0 0.0.0.0:22              0.0.0.0:* LISTENif(0. $tcp0      0 115.28.204.58:58433     42.156.166.25:80Establishedoff(0. $tcp0      the 115.28.204.58:22        59.71.67.114:21489Established on(0.4$udp0      0 115.28.204.58:123       0.0.0.0:*off(0. $udp0      0 10.144.81.226:123       0.0.0.0:*if(0. $udp0      0 127.0.0.1:123           0.0.0.0:*off(0. $udp0      0 0.0.0.0:123             0.0.0.0:*off(0. $UDP 60      0:::123:::*

Can be used to view all network layer connection conditions on the server.

W

The W command is used to view the load condition of the server, enter W, and the command output is as follows:

16:59:52updays, 18:20,  user,  loadaverage: 0.09, 0.04, 0.05USER     TTY        LOGIN@   IDLE   JCPU   PCPU WHATroot     pts/0     16:51    0.00s  0.06s  0.00s w

The results include the server's uptime (4 days,18:20), the number of users, the current user and the program it runs, and the three values for load average are 1-minute, 5-minute, and 10-minute average loads, respectively.

The average value is calculated every 1 minutes, 5 minutes, and 10 minutes for the currently running task and the number of tasks waiting for disk I/O per 5s recording system, which is the mean load.

Df

The DF command is used to view the disk, enter Df-h

Filesystem    Size  used Avail  Use% mounted on/Dev/xvda1      +G  2.1G    $G   6% /Devtmpfs        489M     0  489M   0%/devTmpfs           497M     0  497M   0%/dev/shmTmpfs           497M    +M  478M   4%/runTmpfs           497M     0  497M   0%/sys/fs/cgroupTmpfs            -M     0   -M   0%/run/user/0

You can see the disk usage, the directory of the mounting disk, and so on.

Free

The free command is used to view the memory status

                    total     used       free     shared    buffers     cachedMem:       1016656     940168       76488      19384     114052     543612-/+ buffers/cache:     282504     734152Swap:            0          0          0

You can see the total memory size, the memory used, and the remaining memory.

Swap is a swap partition that can be understood as virtual memory

Iostat

Io is I/O, this command is used to output I/O-related data, input iostat-x

Linux3.10.0-123.9.3. el7.x86_64 (IZ28YQVMJKRZ)Geneva/ -/ ._x86_64_(1CPU) Avg-cpu:%user   %nice %system %iowait  %steal   %idle           0. +    0.xx    0. -    0. .    0. -   99.47device:rrqm/swrqm/sr/sw/srkb/swkb/sAvgrq-sz Avgqu-sz A$xvda0.xx     0. -    0.Ten    0. -     0.94     5.14    28.83     0. on   2$

Device represents the data for a disk device

Ps

This command is used to view process information, enter Ps-aux

USER PID%cpu%MEM VSZ RSS TTY STATSTART    TimeCommandroot1  0.0  0.3 188792  3804? Ss Mar150:Ten/usr/lib/systemd/syste$root2  0.0  0.0      0     0? S Mar150:xx[Kthreadd]root3  0.0  0.0      0     0? S Mar150: on[ksoftirqd/0]root5  0.0  0.0      0     0? s< Mar150:xx[kworker/0:0H]root7  0.0  0.0      0     0? S Mar150:xx[migration/0]root8  0.0  0.0      0     0? S Mar150:xx[Rcu_bh]root9  0.0  0.0      0     0? S Mar150:xx[rcuob/0]......

You can output the use of process identifiers, CPUs, memory, and so on.

PS parameters are many, remember a few commonly used, have special needs when re-check information

Several Linux commands to understand the performance profile of a Linux system