Knowledge Base:All available memory is being used
When calling the free command to see the available memory, users notice that all memory is in use and therefore not available for applications anymore:
total used free shared buff/cache available Mem: 7974 5721 61 0 2192 2154 Swap: 8205 20 8184
A more human readable output is available with the
total used free shared buff/cache available Mem: 7.8Gi 5.6Gi 6.1Mi 0Ki 2.1Gi 2.1Gi Swap: 8.0Gi 20Mi 8.0Gi
This article is applicable to all Linux systems.
The output of the free command is correct, but often misinterpreted.
- The free column in the Mem: row tells the user how much memory is not used for anything, including buffers or cache (which can be removed at any time when memory is needed).
- The buff/cache column in the Mem: row show how much memory is currently used by buffers and cache (mostly used for file system caching), which is memory that can be immediately reclaimed for applications (and as such should be seen as free for applications)
To know how much memory is available for applications (if they need it), one should read the available column on the Mem: line, as that includes free memory + memory used by buffers and cache.
In the above example, more than 2 GiB of memory is available for applications.
- Linux ate my ram! — An entire site dedicated to the misinterpretation of available RAM in Linux.