system:memory:usage

The command "free -m" is used to display the amount of free and used memory in a Linux system, measured in megabytes.

Here's a breakdown of the command:

• "free" is the name of the command itself.
• "-m" is an option passed to the command. The "-m" option is used to display the memory values in megabytes.

When you execute the "free -m" command in a terminal or command prompt, it will provide an output similar to the following:

           total     used     free   shared  buffers   cached

Mem: 7976 3730 4246 0 57 1850 -/+ buffers/cache: 1823 6153 Swap: 4095 0 4095

The output is divided into three sections:

1. Memory: This section provides information about the system's physical memory (RAM). It includes the following columns:

   • Total: The total physical memory (RAM) available.

   • Used: The amount of RAM being used by the system.

   • Free: The amount of unallocated RAM available for use.

   • Shared: The amount of shared memory available.

   • Buffers: The amount of memory used by buffered data (disk-related transfers).

   • Cached: The amount of memory used by the page cache (disk-related data that is kept in memory).

2. -/+ buffers/cache: This section provides information on the RAM utilization, excluding the memory used by buffers and cache. It includes the following columns:

   • Used: The amount of RAM being actively used by processes.

   • Free: The amount of unallocated RAM available for use.

3. Swap: This section provides information about the system's swap space. Swap space is an extension of physical memory that is used when the RAM is full. It includes the following columns:

   • Total: The total swap space available.

   • Used: The amount of swap space being used.

   • Free: The amount of unallocated swap space available.

Overall, the "free -m" command helps to monitor the memory usage of a Linux system, allowing users to understand how memory is being utilized and if there are any potential constraints or bottlenecks.