Memory

Glances uses two columns: one for the RAM and one for the SWAP.

If enough space is available, Glances displays extended information for the RAM:

Stats description:

percent: the percentage usage calculated as (total-available)/total*100.
total: total physical memory available.
used: memory used, calculated differently depending on the platform and designed for informational purposes only. It’s compute as following:

used memory = total - free (with free = available + buffers + cached)
free: memory not being used at all (zeroed) that is readily available; note that this doesn’t reflect the actual memory available (use ‘available’ instead).
active: (UNIX): memory currently in use or very recently used, and so it is in RAM.
inactive: (UNIX): memory that is marked as not used.
buffers: (Linux, BSD): cache for things like file system metadata.
cached: (Linux, BSD): cache for various things.

Additional stats available in through the API:

available: the actual amount of available memory that can be given instantly to processes that request more memory in bytes; this is calculated by summing different memory values depending on the platform (e.g. free + buffers + cached on Linux) and it is supposed to be used to monitor actual memory usage in a cross platform fashion.
wired: (BSD, macOS): memory that is marked to always stay in RAM. It is never moved to disk.
shared: (BSD): memory that may be simultaneously accessed by multiple processes.

A character is also displayed just after the MEM header and shows the trend value:

Trend	Status
`-`	Mean 15 lasts values equal mean 15 previous values
`↓`	Mean 15 lasts values is lower mean 15 previous values
`↑`	Mean 15 lasts values is higher mean 15 previous values

Alerts are only set for used memory and used swap.

Legend:

Note

Limit values can be overwritten in the configuration file under the [memory] and/or [memswap] sections.