Free use and interpretation

#free [parameters] shows free, used physical memory and swap memory in Linux system, and buffer used by the kernel

-H Auto-convert unit easy-to-read mode

-B Displays memory usage in bytes.

-K displays memory usage in kilobytes.

-m displays memory usage in megabytes.

-G displays memory usage in gigabytes.

-O does not display buffer throttling columns.

-s< interval seconds > Continuous observation of memory usage.

-T displays the memory sum column.

-V Displays version information.

#free--------total:used:free:shared:buffers/cached: Total memory Size: Used: Available: Total memory shared by multiple processes: size of disk cache: (-/+ buffers/ Cached): Used:free: How big is used: How much is available: swap:2.0g 0B 2.0G

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-Buffers/cached= Used (first line)-buffers-cached

is actually the size of the "physical Memory" of the program's current "real use".

+ buffers/cached= buffers + Cached

The combination of the two can be interpreted as "temporarily lending" the memory size used by the system as a "buffer".

Buffer is actually used to store the file system's meta data

Cache caches the contents of recently read-write files

Available RAM = System free Memory + buffers + cached.

=total-buff/cach used

Cat/proc/sys/vm/swappiness

Swappiness=0 indicates maximum use of physical memory and then swap space

SWAPPINESS=100 indicates active use of the swap partition, and the memory data is moved to the swap space in time

Echo 3 >/proc/sys/vm/drop_caches

"3" means releasing all buffers and cached; normal use will rise again.

This article is from the "mediocre" blog, please be sure to keep this source http://zzjasper.blog.51cto.com/9781564/1833706

Free use and interpretation