Nagios plugin check_available_memory

• provides a better estimate of "free" memory than standard plugin
• uses the kernel's "MemAvailable" metric
• degrades gracefully to less accurate metrics if this isn't present
  (1st choice) MemAvailable
  (2nd choice) MemFree + Buffers + Cached + SReclaimable
  (3rd choice) MemFree + Buffers + Cached

Usage

• standard Nagios parameters are used for WARNING/CRITICAL limits, but in this case we expect to be triggering on a low value not a high value, so to warn at 25% use option "-w 25:" (note the trailing colon)

• both verbose "-v" and very verbose "-vv" return more detail

• Warn at 25%, critical at 10%
  $ ./check_available_memory.pl -w 25: -c 10:
$ ./check_available_memory.pl --warning=25: --critical=10:

• Online help
  $ ./check_available_memory.pl -h

Licence

See attached LICENCE.txt