pfSense Processes/Memory 0% for period of time



  • Hi everyone,

    I have been using pfSense for a couple of years on PCEngines APU hardware without issue. I recently setup a system with APU2 hardware for a family member and the complaint was that there was no internet. I wasn't able to VPN in for a while but eventually I was able to. I assumed it would have been a modem issue so I went to check the WAN quality under Monitoring but the default graph was set for System/Process and I noticed stretches of 0% for user util, nice util, system util, interrupt, and processes. Same for Memory/States/Mbuf Clusters - all had corresponding utilization of 0% for the same time frame. The only other oddity I noticed was that the SWAP memory was at 95% utilization.

    Has anyone seen something like this?

    -Eddie


  • Netgate Administrator

    Most likely it stopped logging stats for that period. Or lost them if it's running ram disks.

    The cause of that could be a number of things. Did it also stop logging to the system log during that time? If not check there.

    Steve



  • Hi Steve,
    Thanks for the reply!

    I took a look at the system logs like you suggested and there are thousands of "swap_pager_getswapspace(4): failed". They seem to stop at the same time the System/Process' begin again...So it seems safe to say they are probably related.

    Is the SWAP space a fixed percentage of the Disk space by default and partitioned during install? I don't remember configuring it anywhere and my system seems to have double the SWAP space then the one I set up for my family member (his disk is half the size of mine ~14GB)

    I guess I will have to keep an eye on it if it happens again and check pfTop for the potential culprit,

    -Eddie


  • Netgate Administrator

    There are a number of things governing swap size. By default it will be double the RAM size but if the drive is small that can limit it. I forget exactly what to.
    If you see your system using swap at all there almost certainly something misconfigured. Or at least badly configured for that system. Probably a package.

    Steve



  • @stephenw10
    Thanks Steve,

    SWAP partition is ~700MB and after reboot system is currently using using ~10%. I used the guided install so it made the decision for me! Our systems are identically configured (snort/squid/squidguard - to protect the kids somewhat!)
    The only difference between the two systems is his system is using the latest BIOS (updated it 2 weeks ago) where mine is a few versions behind - wonder if it could be related or just coincidence!

    -Eddie


  • Netgate Administrator

    I doubt the BIOS makes any difference there. Something is different though. Your similarly configured system uses no swap?

    With Snort installed make sure the logs are being rotated correctly. In Snort > LogsMgmt set 'Enable Directory Size Limit' and set a suitable size limit.

    Steve



  • After the reboot, the offending system is using 9% of 763MB, my system is using 5% of 1527MB...so roughly the same.

    I tried your suggestion to enable the Directory Size Limit but it will not save..

    -Eddie


  • Netgate Administrator

    Does it show an error when you try?

    So both systems are using SWAP space even immediately after a reboot?

    Steve



  • At the time, Enabling and Saving caused the browser to appear to "refresh" and then the check in Enable Directory Size Limit was empty. It saved after I rebooted the system an re-tried.

    As for the SWAP, after rebooting my system the SWAP was temporarily 0% but it jumped to 20% (of 1872MB) around 10minutes in when the RAM spiked to 98%. Within a few seconds of reaching 98%, the RAM returned to 60% and SWAP was at 20%

    Eddie


  • Netgate Administrator

    Hmm, OK well you need more RAM or less stuff using it. You can certainly tune Snort and Squid to use less.
    There are a number of threads about both.

    Steve


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