Linux system daily management 1 W,VMSTAT,TOP,SAR,FREE,PS monitoring command

One, W, uptime

Command W, uptime

[[Email protected] ~]# W 04:02:31 up 1 day, 8:25, 1 user, Load average:0.00, 0.00, 0.00USER TTY from   [Email protected] IDLE jcpu PCPU whatroot pts/0 192.168.21.103 23:38 0.00s 0.47s 0.13s W

System load averages: Number of processes active in the unit time period

The first set of numbers: represents the average load for the last 1 minutes, which if it is larger than the number of cores in the CPU, it means that the resources are insufficient

Second word number: represents the last 5 minutes average load

Third set of numbers: represents the average load for the last 15 minutes

Ab-n 10000-c ' http://www.ypl.cc/forum.php '

It means that at the same time 100 people go to visit this picture, altogether lasts 10,000 times

-N: How many times are requested

-C: How much is concurrency

View the number of CPUs and the number of cores

Cat/proc/cpuinfo

Cat/proc/cpuinfo |grep ' core ID '

Viewing CPU emulation threads

Uptime: Shows how long the system has been running and the average load on the system

Second, Vmstat command

Vmstat: Displays the status of virtual memory, Syntax Vmstat (options) (parameters)

Vmstat 1: Show status every 1 seconds

Vmstat 1 10: Show every 1 seconds, perform 10 auto-end

Procs: Process-related

Memory: RAM-related

Swap: associated with the swap partition

System: Systems-related

IO: HDD-related

Vmstat the meaning of each indicator:

R: Indicates the number of processes running and waiting for CPU time slices, if the long-term is greater than the number of server CPUs, it indicates that the CPU is not enough;

B: Indicates the number of processes waiting for a resource, such as waiting for I/O, memory, and so on, if the value of this column is greater than 1 for a long time, then you need to look at

Si: The amount of memory entered by the switching zone;

So: the number of memory into the swap area;

BI: The amount of data read from a block device (read disk);

Bo: The amount of data written from a block device (write disk);

In: Number of interrupts per second, including clock interrupts;

CS: The number of context switches per second;

WA: Represents the percentage of CPU time consumed by I/O waits.

Percentage of Us:cpu

Third, top command

The system resources used for dynamic monitoring processes change every 3 seconds.

RES: This is the amount of memory that the process occupies,

%MEM: Percentage of memory to use. In the top state, press SHIFT + M to sort by memory usage size.

Press the number ' 1 ' to list the usage status of each CPU.

TOP-BN1: Represents non-dynamic printing system resource usage, which can be used in shell scripts

TOP-C: Can display more detailed information

RT: Real-time priority

Iv. SAR Command

The system does not install this command by default and requires installation

Yum Install-y Sysstat

Network card traffic

Sar-n DEV 1

Check the network card traffic status for 1 seconds

Sar-n DEV 1 10

Check traffic conditions like 1 seconds, perform 10 consecutive times

Sar-n dev-f/var/log/sa/sa24

View network card traffic history for the 24th day

View Historical Load Sar-q

View disk read-write Sar-b

V. FREE command

Free to view system memory usage

Free is displayed as a unit of K

Free-m in units of M

Free-g in G

MEM (total): Number of memory;

MEM (used): already allocated memory;

Mem (free): unallocated memory;

MEM (Buffers): system-assigned but not used buffers;

MEM (cached) system allocated but not used cache

Buffers/cache (used): actual use of buffers and cache total, but also the actual use of memory, Buffers/cache (free): unused buffers and cache and unallocated memory of the sum, This is the current actual memory available to the system

The buffers is about to be written to the disk, and the cache is read from the disk.

Six, PS View system process

PS aux/ps-elf

PS aux: List all processes of the system

Ps-l: Displays only the processes running in the foreground under the current user

PID: The ID of the process, this ID is very useful, in Linux kernel management process relies on PID to identify and manage a certain process, such as I want to terminate a certain processes, then the ' kill process pid ' sometimes do not kill, you need to add a-9 option kill-9 process PID

STAT: Indicates the status of the process, and the process state is divided into the following

D a process that cannot be interrupted (usually IO)

R Running Process

S has been interrupted, and most of the process in the system is this state

T has stopped or paused the process, if we are running a command, say sleep 10 if we press Ctrl-z to let him pause, then we will show the status of T in PS view

X already dead process (this never appears)

Z zombie process, can't kill, fight the garbage process, the system a small resource, but no relationship. If too many, there is a problem.

< high-priority processes

N Low-priority processes

L was locked in memory paging

S master Process

L Multithreading Process

+ Process in the foreground

Pstree Tree Show All Processes

Netstat viewing network conditions

NETSTAT-LNP View current system-enabled ports and sockets

Netstat-an View all connections to the current system

This article is from the It Exchange Learning blog, so be sure to keep this source http://sxct168.blog.51cto.com/824373/1658807

Linux system daily management 1 W,VMSTAT,TOP,SAR,FREE,PS monitoring command