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Sysbox: free

Usage: free [OPTION]...

Display amount of free and used memory in the system.

If no options are given, the display unit will be kilobyes (1024 bytes).

The displayed amounts contain the reserved memory as well. See task for details.

The Mem line: Total installed memory. All memory blocks are counted here. However, the kernel-level reserved space is not included here, so the amounts displayed may be lower than the physically installed memory.

The Main line: The main memory block, mainly used by the kernel. It is possible to allocate from it, but it is not allowed by default. Program heaps will not consume this memory area.

The Virt line: Total virtual space, used for virtual memory management.

Options:

• -b, --bytes
  Show the output in bytes.
• -k, --kilo
  Show the output in kilobytes (1024 bytes by default).
• -m, --mega
  Show the output in megabytes (1024*1024 bytes by default).
• -g, --giga
  Show the output in gigabytes (1024*1024*1024 bytes by default).
• -p, --peta
  Show the output in petabytes (1024*1024*1024*1024 bytes by default).
• -S, --si
  Use powers of 1000 instead of 1024. So kilobyte will be 1000 bytes not 1024, megabyte will be 1000*1000 bytes not 1024*1024, etc.
• -h, --human
  Show human-readable output. Round the values and use an appropriate unit.
• -v, --virt
  Display virtual memory as well.

Examples:

$ free -hvS
            total        used        free
Mem:         1.0G         81M        978M
Main:        260M          8M        251M
Virt:      277.0G         73M      276.9G
$