Memory

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

../_images/mem.png

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

../_images/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.
  • 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
- MEM value is equal to the mean of the six latests refreshes
\ MEM value is lower than the mean of the six latests refreshes
/ MEM value is higher than the mean of the six latests refreshes

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.