.. _memory:

Memory

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

.. image:: ../_static/mem.png

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

.. image:: ../_static/mem-wide.png

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 (including ZFS cache).

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.
• percent_min: the minimum memory usage percentage observed since Glances startup.
• percent_max: the maximum memory usage percentage observed since Glances startup.
• percent_mean: the mean memory usage percentage observed since Glances startup.

It is possible to display the available memory instead of the used memory by setting the available option to True in the configuration file under the [mem] section.

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:

======== ============ RAM/Swap Status ======== ============ <50% OK >50% CAREFUL >70% WARNING >90% CRITICAL ======== ============

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