Kubuntu 17.10 is freezing at random times

[kenshiwara]

Hello!

Please, I started recently experiencing random freezing episodes while using Kubuntu 17.10

There is no specific time for this freezing session and the whole desktop environment would become not usable at all. The mouse would slowly move and it would take 20-30 minutes at least to close any window or even to reach the reboot button. Sometimes as well, I won't be able to move my mouse at all. It is very random and it is not related to any program since I only use a simple web browser.

System Information:

• Kubuntu Version: 17.10
• Kernel: x86_64 Linux 4.13.0-21-generic
• KDE Framework Version: 5.40.0
• KDE Plasma Version: 5.11.4
• Kubuntu artful-backports: It is enabled on my system.

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System Specifications:

• CPU: Intel(R) Core(TM) i5-6500 CPU @ 3.20GHz
• RAM: 16,362,112 kB
• Motherboard: Z170-P D3 (ASUSTeK COMPUTER INC.)
• Graphics: 3840x2160 - GeForce GTX 1050 Ti/PCIe/SSE2 - The X.Org Foundation

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Other Information:

• The dmesg or KSystemLog is showing the following: https://paste.ubuntu.com/26325177/
• The contents of the syslog file can be checked at: https://paste.ubuntu.com/26325448/
• The journalctl --priority 2..3 command is returning the following:https://paste.ubuntu.com/26325512/
• The sudo smartctl -a /dev/sda is returning the following: https://paste.ubuntu.com/26325550/
• The contents of the ~/.xession-errors are as follows: https://paste.ubuntu.com/26325618/

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Typing

free

at the moment - while the operating system is working well - shows the following:

	Total	Used	Free	Shared	Buff/Cache	Available
Memory	16362112	3773316	10525808	151196	2062988	12128992
Swap	16707580	0	16707580

Update - I just had a freezing session, so I did exactly what you told me to do. I accessed the terminal using CTRL + ALT + F1, then typed

free

after logging in. The results were different this time, as follows:

	Total	Used	Free	Shared	Buff/Cache	Available
Memory	16362112	15431876	200896	433108	729340	219008
Swap	16707580	87808	16619772

Note: I noticed as well that simply logging off then logging in again from the terminal using

loginctl terminate-user $USER

is resolving the issue. Of course, I am losing all my opened work but at least no reboot will be required.

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The other temporary solution I came up with - apart from the logging off method mentioned above - to break this freezing session and return back to my system goes as follows:

Step 1: Access the terminal using:

[B]CTRL + ALT + F1[/B]

Step 2: Login with my username.

Step 3: I would kill all processes using:

[B]kill -9 -1[/B]

Step 4: Logging back to the desktop environment using:

[B]CTRL + ALT + F7[/B]

Note: Of course, Step 4 would hit an error related to the dbus since I killed all the processes above so I have to startx using (sudo startx) then I need to change the owner of the Xauthority back to my username to avoid the famous login loop using (chown $USER:$USER .Xauthority).

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Basically, I want to know if the issue is software or hardware.

Your help will be greatly appreciated! Thanks in advance.

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Update: This issue has been resolved using the tips suggested by the great members on here. The problem turned out to be from two apps (ManageYum) and (All-In-One Messenger). If you face a similar problem, simply install the htop tool to track the memory usage and see which programs are causing the problem.

[oshunluvr]

Sounds like full memory. System specs please. Next time you get into this, in the terminal mode, type "free" and see if swap has a number other than 0 under "used".

[kenshiwara]

Sounds like full memory. System specs please. Next time you get into this, in the terminal mode, type "free" and see if swap has a number other than 0 under "used".

Thank you very much for your reply.

I have already updated the original post with your requested information. I will also update it again - with the current values of memory and swap once my system freezes.

[GreyGeek]

What does dmesg or KSystemLog show?

[kenshiwara]

What does dmesg or KSystemLog show?

@GreyGeek - Thank you very much for your reply. I have already updated the original post with all the required information.

The dmesg or KSystemLog is showing the following: https://paste.ubuntu.com/26325177/


@oshunluvr - I have updated the original post with the table that I am getting with the "free" command during the freezing episode. Thanks again for all your help.

I hope you can help me in debugging this issue.

[chimak111]

... since I only use a simple web browser.
...

So is this browser running at the time you encounter problems? Which is this browser? What sort of tabs are open in the browser?

[kenshiwara]

So is this browser running at the time you encounter problems? Which is this browser? What sort of tabs are open in the browser?

I changed the browser over the past few days but that did not help. I am using currently Google Chrome (the latest stable version). I only use few tabs for checking the emails and updating my sites. There is nothing fancy that would consume the memory in any crazy way. I also use a messaging app (ManageYum) for tuning my Skype and WhatsApp. However, even without using this program, the system is still experiencing those freezing issues at random times.

The main problem is that I am still not sure if the problem is hardware or software related. Thank you for your help!

[oshunluvr]

	Total	Used	Free	Shared	Buff/Cache	Available
Memory	16362112	15431876	200896	433108	729340	219008
Swap	16707580	87808	16619772

As I suspected, something is "eating" up your 16GB of RAM. When your system starts using SWAP, it slows waaayyy down, which explains the mouse etc. This is usually caused by a "memory leak" - a program or piece of software that consumes memory, but does not release it back to the system when done with it. This eventually fills your system as you see happening.

Here's what I would do:

Boot up, log in, open konsole and no other programs.
In konsole install "htop": sudo apt install htop
Once installed, run htop: htop
On the green bar of the now running htop, click on MEM%
This will sort the list of running programs by the amount of memory they consume.

Now simply wait until you see a program take the top position and you will see the MEM% number increase. I don't recall if you stated how long this condition takes to occur, but if it's lengthy, just go do a chore or something and come back. After what you feel like is enough time has passed, nothing has changed significantly, launch your "simple browser" and see if that's the culprit. If not, continue using the machine as you normally would until something rises to the top and starts to grow.

Then post back and we'll discuss options to fix it.

I've seen this on my system three times. One was a poorly written Plasma Widget, one was a Web Browser, one was a Video Editor. I'm guessing in your case it will be either a widget or your browser.

[chimak111]

BTW, have you allowed Google Chrome to run in the background? Look at the bottom of the page when you paste

chrome://settings/?search=background

in your Google Chrome browser and press enter. If you have, try turning it off.

[kenshiwara]

BTW, have you allowed Google Chrome to run in the background? Look at the bottom of the page when you paste

chrome://settings/?search=background

in your Google Chrome browser and press enter. If you have, try turning it off.

Thank you for your suggestion. It is off already.

@oshunluvr - Thank you very much for your help and reply. I installed htop already and I am waiting now for the freezing episode to happen again. Once it does, I will check the memory consumption using that tool and report back on this forum.

[GreyGeek]

This will get rid of your multicast listings:
sudo ufw deny to 224.0.0.1
sudo ufw reload

[kenshiwara]

This will get rid of your multicast listings:
sudo ufw deny to 224.0.0.1
sudo ufw reload

Thank you very much to all! The issue has finally been resolved.

The problem was happening because of two apps:

ManageYum - https://manageyum.com/
All-In-One Messenger - https://allinone.im/

Both of the above apps were consuming my RAM and not releasing it back to the system. I managed to find them using the tool htop.

Deleting them solved my problem instantly and I verified that over the course of several days while monitoring the memory usage very closely.
I did not report this bug to the developers of those applications since I don't think I will ever use them again.

All the best!

For Reference: htop - https://en.wikipedia.org/wiki/Htop