1 title: Detailed usage of RAM, Swap, VMalloc and other memory areas on Linux
7 This check measures all of the available memory readings of the complex
8 Linux memory management, which are found in {/proc/meminfo}. You can
9 define levels on every useful value, not only on RAM and Swap. Please
10 note that the Linux memory management is very complex. This check takes
11 all this into account and also correctly handles the concept of
12 caching and the fact that Linux swaps out inactive parts of processes
13 even if there is enough RAM left.
15 This is not a bug, it's a feature. In fact it is the only way to do it right
16 (at least for Linux): What parts of a process currently reside in physical
17 RAM and what parts are swapped out is not related in a direct way with the
20 Linux tends to swap out parts of processes even if RAM is available. It
21 does this in situations where disk buffers (are assumed to) speed up the
22 overall performance more than keeping rarely used parts of processes in RAM.
24 For example after a complete backup of your system you might experiance
25 that your swap usage has increased while you have more RAM free then
26 before. That is because Linux has taken RAM from processes in order to
27 increase disk buffers.
29 Per default there are various crit/warn levels set. Please use WATO
30 for viewing and adapting these levels.
36 One item per Linux host is being created.