A few times a day the system starts lagging (about 1-2 seconds) with sensors showing high "busy time" on /home (not /)
by Lockywolf from LinuxQuestions.org on (#4V5K4)
Hello, everyone.
It is a bit hard to explain the problem. Once in a while the system starts being not responsive. It starts taking about a second or two to respond to input, to switch desktops in Xorg, and ping jumps up by about 3000.
This can last for some time, up to about an hour, and then suddenly disappear, as if it hasn't been.
I have not found anything definitively correlating with the slowliness period, but did find some loosely correlated things. 1) jumps in "dentunusd" field in /var/log/sa , but they also sometimes happen without any lags, 2)lags seem to appear less prominent when the laptop fan speed is set to "high", which on my Dell E6420 is done with the two tools:
Code:dell-bios-fan-control 0
i8kctl fan 2 2This is a bit weird, because there seems to be no correlation with the actual _temperature_. The lags can easily happen with a cold laptop.
I heard that some Dell laptops had a problem with lm_sensors which led to long freezes, because often a controller carries one fan, whereas a controller in general supports two, and this leads to confusion of the sensors module. However, even though my laptop only carries one fan, there seems to be no problem running "sensors".
The lags seem to affect Linux terminal less or even not at all. That is if I switch from XFCE to Ctrl-Alt-F1, the text console is responding quickly. However, pings to a nearby webserver are still very laggy.
Could someone suggest some more debugging methods?
I use Slackware-current. The problem appears both on the last kernel 4.16, and on 5.4.0-rc7. Root (/) is on an HPE SSD LK0480GFJSK, /home is on a magnetic drive Western Digital WDC WD20SPZX-22CRAT0.
The laptop is Dell E6420, 16Gb of RAM, Intel(R) Core(TM) i5-2520M CPU @ 2.50GHz, Turbo disabled.
It is a bit hard to explain the problem. Once in a while the system starts being not responsive. It starts taking about a second or two to respond to input, to switch desktops in Xorg, and ping jumps up by about 3000.
This can last for some time, up to about an hour, and then suddenly disappear, as if it hasn't been.
I have not found anything definitively correlating with the slowliness period, but did find some loosely correlated things. 1) jumps in "dentunusd" field in /var/log/sa , but they also sometimes happen without any lags, 2)lags seem to appear less prominent when the laptop fan speed is set to "high", which on my Dell E6420 is done with the two tools:
Code:dell-bios-fan-control 0
i8kctl fan 2 2This is a bit weird, because there seems to be no correlation with the actual _temperature_. The lags can easily happen with a cold laptop.
I heard that some Dell laptops had a problem with lm_sensors which led to long freezes, because often a controller carries one fan, whereas a controller in general supports two, and this leads to confusion of the sensors module. However, even though my laptop only carries one fan, there seems to be no problem running "sensors".
The lags seem to affect Linux terminal less or even not at all. That is if I switch from XFCE to Ctrl-Alt-F1, the text console is responding quickly. However, pings to a nearby webserver are still very laggy.
Could someone suggest some more debugging methods?
I use Slackware-current. The problem appears both on the last kernel 4.16, and on 5.4.0-rc7. Root (/) is on an HPE SSD LK0480GFJSK, /home is on a magnetic drive Western Digital WDC WD20SPZX-22CRAT0.
The laptop is Dell E6420, 16Gb of RAM, Intel(R) Core(TM) i5-2520M CPU @ 2.50GHz, Turbo disabled.