I’m looking for help regarding a relatively new installation of Ubuntu Mate 16.04 LTS.
A few months ago I changed over an older PC from Windows XP to Ubuntu MATE (yes, it was long overdue). I made sure the system was up to date and then the only application I installed was Private Internet Access.
For the first little while everything was working fine. However, recently the system has started to become unresponsive after about a day of up time. Sleep mode, hibernate, etc. is turned off. Nothing wakes the system. Mouse clicks, space bar, enter, etc. The monitor sits there blinking it’s light as if the PC wasn’t turned on (it is on).
It is not a graphic issue either as I have the PC on a network and it becomes inaccessible.
My main question is, where do I start? I looked in /var/log/messages and it is empty. I’m not sure where else to check. I’m guessing there is an error log somewhere that could tell me more information of what’s happening. Can anyone point me in the right direction?
Also, another troubleshooting step I did was I updated the system again. A few days ago I went ahead and updating everything (including the kernel). The system still becomes unresponsive after about a day.
Hallo FelixTheBat
Suggestion 1
Go to Applications > System Tools > “Mate System Monitor”. Select the “Resources” tab and look at your “Memory and swap history”. Leave this open after re-booting your machine and check it periodically until the point where the machine becomes unresponsive.
My guess…
You may have a minimum amount of RAM and the RAM-usage of your installation “grows” with time.
Question 1
Could you please provide information regarding how much RAM your computer has and also the cpu?
If you don’t know, open a terminal (CTRL+Alt+T) and enter:
sudo inxi -m
You may also find the output generated by:
sudo inxi -t cm
to be interesting/useful.
Question 2
32 bit or 64 bit installation?
Question 3
If you do a fresh install, without adding “Private Internet Access” does this problem still occur?
Suggestion 2:
If this is a RAM problem, you may be able to add more RAM to your machine, depending upon the maximum amount supported by your mother board and cpu.
Good hunting! 
It’s a Pentium 4 3.2 GHz CPU with 2 GB of RAM (2x 1 GB) sticks. It’s running a 32-bit installation of Ubuntu MATE.
With regards to usage, inxi -t cm shows openvpn is the top CPU usage at 3.1%. The top memory usage is pia_nw at 42.5 MB.
In terms of system resources, the reported usage is:
CPU1: 4.0%
CPU2: 4.0%
Memory: 559.8 MB (27.8%) of 2.0 GB
Swap: 35.6 MB (1.7%) of 2.0 GB
I’ll keep an eye on the memory usage to see if it increases. As of now, it seems reasonable and no where near max capacity. As for a fresh install without Private Internet Access I will give that a try as soon as I can (have family over this weekend).
So RAM and CPU has seem normal. Nothing really increasing much. Just fluctuating. Issue is still occurring. It actually just happened within an hour this time.
Not sure how to proceed. It’s really hard to tell without knowing where any logs are. Usually issues such as kernel panics (as an example) are logged. I have no idea what to do.
