18.04 freezes with a old laptop

I have a rather old laptop, but I am particularly attached to it and would like to continue using it, if at all possible.

A couple of months ago, I updated the Lubuntu version from 14.04 LTS to 18.04 LTS and, unfortunately, I immediately ran into the problem of random freezes, especially if using Thunderbird and Chromium.

These are complete freezes, where the display is completely frozen, blinking lights for HDD access stop, and I cannot switch to terminal with CTL+ALT+F1, nor use REISUB or any other trick that I have read in this community.

One first thing I did was to run Memtest+ for half a day, but the test did not highlight any memory failure.

Looking at the log files, both with journalctl -b or in Xorg.0.log, did not give me any hint of where the problem might be because they don’t record any useful information on the freeze.

Trying to make it more robust, I tried the following things:

All the actions are not cumulative, meaning that I tested them starting from boot and editing the boot line in GRUB, then proceeding to login and open the same application(s).

Do you have any idea of how I troubleshoot and fix the cause for these crashes?

As a test, I run Lubuntu 18.04 from a usb and it also froze after some time I was navigating in Internet with Chrome and Firefox.

Doing the same experiment with Lubuntu 14.04, which I had available in USB stick, it wasn't freezing at all.

Unfortunatly, after several attempts to find why my laptop freezes i could not find any solutions.

In the past few weeks I tried:

• Checking the CPU temperature with acpitool -e but the temperature from the CPU is not reported
• Tried to detect thermal sensors with sensor-detect but none are found
• Checked if there is any driver managing the CPU power and found in acpi-cpufreq passive managemnt of the power, no active management of fans

The point I find strange is that the laptop works quite well if I connect with ssh and use it remotelly, but when I use the desktop environment, especially any browser, after a while it stops completely with HDD LED OFF, fan sometimes ON, no response whatsoever.

Solution 1:

Finally, I was able to get to a stage where the system is no longer freezing.

First of all, I noticed that the system was freezing mainly when there were applications using the network, like Thunderbird, Chromium Firefox and the like, when clicking to access some content, but would not freezing if using applications not using it.

This prompted me to:

• Check if the NetworkManager was posting any error in the logs by reviewing the journal with sudo journalctl -b. However, I could not see any error related to the network card or network configuration.
• I also checked if the traffic of the network sockets was normal with ss -tan and ethtool eth0 and tcpdump -ni eth0 but I couldn't find anything strange with the output of these commands.
• Therefore, I resolved to install strace with sudo apt-get install strace
• Create a directory to store the strace output mkdir ./Downloads/strace
• Run Chromium, Firefox or thunderbird under that tracer, for example strace -C -f -c ./firefox &>straceoutput.txt
• Examined the output of the various programs with vi straceoutput.txt especially at the bottom of the file SHFT+g to see what the program was doing last, just before hanging
• Noticed that the point where the programs were hanging showed access to networks services

[pid 1757] recvmsg(4, {msg_namelen=0}, 0) = -1 EAGAIN (Resource temporarily unavailable) <0.000028> [pid 1757] poll([{fd=4, events=POLLIN}, {fd=5, events=POLLIN}, {fd=33, events=POLLIN}], 3, 0) = 0 (Timeout) <0.000028>

With this hint, I could only suspect that the access to the network was not working properly, therefore I disconnected the lan cable and connected to the WiFi so as to switch network access.

Changing the network access for the WiFi made the trick and allows me to work without hangs.

I can consider the issue of old PC hanging with the 18.04 SOLVED and will open a new question to understand why the NIC connection is failing.