Hi, are there any standard daemons (time-based or system-triggered) that purge /dev/shm ? I noticed that the complete tmpfs on /dev/shm is cleaned at some points, which is a bit unlucky when some processes have files located there. I monitored the pruges but found no obvious pattern. For the monitored machine the purges take place during early morning but not at fixed times (and all checked crons seem to be innocent). As for the memory consumption (as my second suspected trigger) I am not sure if it is significant
For example, my /dev/shm was purged today morning between 3:00-3:05 and the memory usage around that time looked as: Tue Jul 26 02:45:01 CEST 2011 MemFree: 2113876 kB Active: 14873624 kB Inactive: 6345556 kB Tue Jul 26 02:50:01 CEST 2011 MemFree: 1836656 kB Active: 15255568 kB Inactive: 6194388 kB Tue Jul 26 02:55:02 CEST 2011 MemFree: 628992 kB Active: 15924712 kB Inactive: 6729112 kB Tue Jul 26 03:00:01 CEST 2011 MemFree: 770884 kB Active: 15472048 kB Inactive: 7046180 kB Tue Jul 26 03:05:01 CEST 2011 MemFree: 1403260 kB Active: 16327832 kB Inactive: 5556164 kB Tue Jul 26 03:10:01 CEST 2011 MemFree: 848168 kB Active: 16849468 kB Inactive: 5600408 kB (with tmpfs up to 20000m from a total memory of 24GB) What is the standard kernel behaviour to treat /dev/shm if the free memory reaches 0? -- at least in my coarse time binning the free memory seems to get depleted (I would have expected the kernel to start swapping onto disk...) Or is there probably another explanation why /dev/shm is purged? Cheers and thanks for all ideas?, Thomas
