Hi. On Sat, Aug 25, 2018 at 06:07:01PM +0530, Subhadip Ghosh wrote: > > > On Saturday 25 August 2018 04:29 PM, Reco wrote: > > Hi. > > > > On Sat, Aug 25, 2018 at 09:42:31AM +0530, Subhadip Ghosh wrote: > > > Hi, > > > > > > I am a Debian testing user. Recently I am experiencing freezing on my > > > Debian > > > system intermittently and during troubleshooting the same, I found out > > > that > > > the I have a swap partition with priority set to -2. > > Same here with stable. > > > > > > > But according to the below manpage: > > > > > > https://manpages.debian.org/stretch/mount/swapon.8.en.html > > > > > > swap priority should be between -1 and 32767. > > So swapon(8) utility has this restriction. Note that the system call > > itself - swapon(2) merely interprets swap priority as a signed integer, > > so any priority number is actually possible (within integer limits of > > course). > > > > > > > I have a swappiness value of 60 but I don't remember seeing the swap > > > being used at all recently, the used swap is always 0%. > > A hint. They invented this wonderful thing called sysstat decades ago so > > you don't have to remember your swap usage, along with other things > > sysstat gathers. > > > > > > > My question is, do you think that the -2 priority is stopping the swap > > > partition from actually being used and because of that, the system is > > > getting frozen when the memory usage is high? > > No, it definitely does not work this way. > > A swap priority only comes into play once you have multiple instances of > > swaps. If you have a single swap partition/lv/file, a priority value is > > meaningless. > > > > A system freezes, on the other hand (did I mention sysstat?), could > > indicate heavy swapping, barrier writes, kernel bugs (12309, anyone?), > > oom killer invocations, overheating and many other things. > > A good starting point would be kernel message log (aka > > /var/log/kern.log) from the time of this freeze. > Thanks for the suggestion. I checked the kern.log but did not find any > suspicious log, in fact no entry from that exact time frame when the last > freeze happened. Do you have any other suggestions to troubleshoot the > freezes?
"sar -r ALL -f 25" and "sar -S -f 25" would be the next logical step. Note that "25" means current date (i.e. 25th of current month). Should be preceeded by "apt install sysstat", of course. Reco
