# free

The results are as follows :

Mem: Represents physical memory statistics

total Total memory 8057964KB
used Used memory 7852484KB
free The amount of free memory 205480KB
shared It has been abandoned , Always 0
buffers Buffer Number of cache memory : 290432KB
cached Page Number of cache memory :5735024KB
( There is relationship between : total = used + free )

-/+ buffers/cached: Represents the cache statistics of physical memory

(-buffers/cache) used Memory count :1827028KB ( The first part of Mem In a row used - buffers - cached)
(+buffers/cache) free Memory count : 6230936KB ( The first part of Mem In a row free + buffers + cached)

-buffers/cache It reflects the memory actually eaten by the program ;
+buffers/cache It reflects the total amount of memory that can be misappropriated ;

Swap: Indicates the usage of the swap partition on the hard disk

free Parameter description
-m With M Check memory usage for units ( The default is kb)
-b With Byte Check memory usage for units
-k With KB Check memory usage for units
-o Do not display cache tuning Columns
-t Display memory sum column
-V Display version information
-s < Seconds apart > You can not simply monitor the memory usage within a specified period of time

buffers And cached The difference between
For applications ,buffers/cached Is equal to available ,
because buffer/cached To improve the performance of file reading ,
When the application needs to use memory ,buffer/cached It will be recycled soon .
So from an application perspective Available memory = System free memory+buffers+cached.

buffers It refers to the buffer size used for block devices ,
He only records the file system metadata as well as tracking in-flight pages.
cached It's used to buffer files .
That is to say :buffers It's for storing , What's in the catalog , Permissions, etc. .
and cached It's directly used to remember the files we opened , If you want to know if it really works ,
You can try it , Two orders in succession #man X , You can obviously feel that the second start was much faster .

Remember that memory is for use , Not to see . Unlike windows, No matter how much physical memory you have , He's always swapping hard drives for File to read .

This is the same. windows Why often prompt the reason that fictitious space is insufficient . Think about it , How boring , There's a lot more in memory When , Take out a part

Hard disk space to act as memory . Hard disk is faster than memory . So let's see linux, As long as no need swap In exchange for Space , You don't have to worry about your memory

too little . If often swap Use a lot , Maybe you should consider adding physical memory . This is also linux see The standard of whether the memory is enough .

LINUX Check out more articles about current system memory usage

  1. LINUX View the memory usage of the current system free

    Learn a little every day Programming PDF e-book . Video tutorial free download :http://www.shitanlife.com/code # free The results are as follows : Mem: Represents physical memory statistics total Total memory 8057 ...

  2. LINUX View the memory usage of the current system vmstat

    Linux vmstat command Vmstat Orders are the most common Linux/Unix Monitoring tools , It can show the state value of the server at a given time interval , Including the server CPU Usage rate , Memory usage , Virtual memory exchange ,IO Reading and writing . comparison ...

  3. How to view centos System cpu/ Memory usage

    1. Check out the hard disk [mushme@investide ~]$ df -ah file system               Capacity   Already used You can use Already used % Mount point /dev/cciss/c0d0p1     123G   ...

  4. linux see Java Memory usage of the process

    top -b -n 1 | grep java| awk '{print "PID:"$1",mem:"$6",CPU percent:"$ ...

  5. linux Sort the processes according to the memory usage

    linux The command to sort processes according to memory usage is :ps aux --sort -rss For a detailed explanation, see http://alvinalexander.com/linux/unix-linux-proce ...

  6. linux see cpu Number , The memory of , System version

    see cpu Number Total number of cores = Physics CPU Number * Every physics CPU The number of nuclear General logic CPU Count = Physics CPU Number * Every physics CPU The number of nuclear * Number of hyper threads View physics CPU Number cat /proc/cpuinfo ...

  7. Linux Check the memory usage of files in the root directory

    One . After the server runs for a while, all kinds of project files , Log files , Database backup , More and more , stay linux You can use du and df Command view . 1.df -h Command to view the overall disk usage 2.  Use du -ah -- ...

  8. Program to get linux Of CPU Memory usage used

    Linux You can use top.ps Command to check the current cpu.mem usage . Here's a simple example : One . use ps View the process of resource consumption ps -aux When you view process information , The third column is CPU To stay in . [root@localhost ...

  9. Linux bandwidth 、CPU、 Memory footprint

    iftop Check the bandwidth usage ( total )yum install -y iftop install iftopnethogs View process traffic curl View out ...

Random recommendation

  1. utilize NABCD Model for competitive demand analysis

    Microblogging NABCD Model N-Need: without doubt , Today's ordinary Chinese people have this demand , In the last century, Chinese people's way of leisure and entertainment more stay in the television based entertainment , And enter 21 Since the 20th century, the entertainment center of the Chinese people has shifted to the Internet , ...

  2. IE Document compatibility in

    Document compatibility can be defined Internet Explorer The way web pages are presented , For details, please refer to  https://msdn.microsoft.com/zh-cn/library/cc288325(v=vs.85 ...

  3. MS SQL Server Time is a common function

    SQLServer Time date function detailed explanation ,SQLServer, Time date , 1.      Current system date . Time select getdate() 2. dateadd      On the basis of adding a period of time to a given date ...

  4. Get to know for the first time CSS3

    What is? CSS, What is? CSS3? It's simple ,CSS representative "Casading Style Sheets", It's the style sheet , It's a markup language that replaces and styles websites . What is used now CSS Basically in 1 ...

  5. Talking about DevExpress&lt; One &gt;: Skin peeler

    It's going to be used recently devExpress, In a word , Good, strong , Compared with vs Self contained winform Interface , There are a lot more kinds and patterns , However , Powerful functions bring a huge amount of information , So I plan to discuss and study it with you through some small modules . ...

  6. Chapter two JavaScript Core grammar

    Chapter two    avaScript Core grammar One . Declaration and assignment of variables JavaScript Is a weakly typed language , There is no explicit data type , That is, you don't need to specify a data type when declaring a variable , The type of variable is determined by the value assigned to it . stay Java ...

  7. Integrated alipay SDK technological process

    5.2 SDK Integration process 5.2.1 iOS Decompress the interface compressed file ( The file name is  WS_MOBILE_PAY_SDK_BASE.zip), find iOS The compressed file of ( The file name is Alipay mobile payment SDK  The standard version (iOS).z ...

  8. Python adopt Zabbix API Get data

    Zabbix API Inquire about :https://www.zabbix.com/documentation/2.0/manual/appendix/api/api import json,urllib2 fr ...

  9. Android A journey in reverse --- Crack &amp;quot; Puss in boots &amp;quot; The charging function of the game

    One . Game fee analysis Game fees are very normal , But the most disgusting thing about playing games is that you have to recharge before you play , Very angry , Actually, I don't play games very much , It's mainly for children , For example, nowadays many kids like to play the fruit ninja game . But the game didn't start ...

  10. angula Study

    introduction http://www.angularjs.cn/A004 http://www.cnblogs.com/whitewolf/p/angularjs-start.html http://www.n ...