How to diagnose an unresponsive Ubuntu 16.04 GUI?

1

Virtually a newbie to linux/ubuntu I recently installed Ubuntu 16.04 AMD64 build on a hard-drive first installing it on a USB stick. The system is now a dualboot with Win 7 on one drive, Ubuntu 16.04 on the other.

Occasionally (in fact almost everytime I use the UI) the Ubuntu hangs at random. This appears to happen regardless of what application runs. The only consistency appears to be that each time this occurs Ubuntu was running in the default GUI (light?) - as long as I'm on a TTY it appears to work fine. As a newbie though I am usually on the GUI though. I took the liberty of upgrading the kernel following the instructions here

The GPU on this system is an ASUS 8400EN. The monitor is a Dell 20".

What should I look for in the syslog to diagnose this issue?

[EDIT/UPDATE]

Following @StandardEye I took a gander at XOrg.0.log. There are no errors reported. This system uses an older P7P55D-E Pro board... running PS/2 keyboard & mouse. The log file appears to be identify the mouse using a trackpad driver

[    38.424] (II) config/udev: Adding input device PS/2 BYD TouchPad      (/dev/input/event3)
[    38.424] (**) PS/2 BYD TouchPad: Applying InputClass "evdev pointer catchall"
[    38.424] (II) Using input driver 'evdev' for 'PS/2 BYD TouchPad'
[    38.424] (**) PS/2 BYD TouchPad: always reports core events
[    38.424] (**) evdev: PS/2 BYD TouchPad: Device: "/dev/input/event3"
[    38.424] (--) evdev: PS/2 BYD TouchPad: Vendor 0x2 Product 0x1
[    38.424] (--) evdev: PS/2 BYD TouchPad: Found 3 mouse buttons
[    38.424] (--) evdev: PS/2 BYD TouchPad: Found relative axes
[    38.424] (--) evdev: PS/2 BYD TouchPad: Found x and y relative axes
[    38.424] (II) evdev: PS/2 BYD TouchPad: Configuring as mouse
[    38.424] (**) evdev: PS/2 BYD TouchPad: YAxisMapping: buttons 4 and 5
[    38.424] (**) evdev: PS/2 BYD TouchPad: EmulateWheelButton: 4, EmulateWheelInertia: 10, EmulateWheelTimeout: 200
[    38.424] (**) Option "config_info" "udev:/sys/devices/platform/i8042/serio1/input/input4/event3"
[    38.424] (II) XINPUT: Adding extended input device "PS/2 BYD TouchPad" (type: MOUSE, id 9)
[    38.424] (II) evdev: PS/2 BYD TouchPad: initialized for relative axes.
[    38.424] (**) PS/2 BYD TouchPad: (accel) keeping acceleration scheme 1
[    38.424] (**) PS/2 BYD TouchPad: (accel) acceleration profile 0
[    38.424] (**) PS/2 BYD TouchPad: (accel) acceleration factor: 2.000
[    38.424] (**) PS/2 BYD TouchPad: (accel) acceleration threshold: 4
[    38.424] (II) config/udev: Adding input device PS/2 BYD TouchPad  (/dev/input/mouse0)
[    38.424] (II) No input driver specified, ignoring this device.
[    38.424] (II) This device may have been added with another device file.

Everyone

Posted 2016-12-05T14:36:58.453

Reputation: 1 714

When you say "as long as I'm on a terminal" to you mean a tty (you can see what those are with Control+Alt+F1/F2/F3/F4) or do you mean a terminal that's in a window (i.e. has a border and a close button)? – timotree – 2016-12-05T17:16:18.647

A TTY rather than a windowed terminal under X – Everyone – 2016-12-05T18:21:11.740

1Sounds like an X issue to me. – timotree – 2016-12-05T18:22:18.913

My thoughts precisely; thing is - what do I look for in syslog to confirm it is indeed an X issue. Or is there a separate log-file maintained for X-server? – Everyone – 2016-12-05T18:29:55.777

I just tagged this as [xorg] so X experts (something I am not) should be able to find this more easily. I do have another clarifying question though. What do you mean by "hangs"? – timotree – 2016-12-05T18:32:10.507

I mean the keyboard/mouse cease to respond. The UI fades mildly yet it continues to update as any application writes output to the relevant stream. For instance, if a chat session is open - anything written by anybody else participating in the chat is visible even after my keyboard/mouse cease to respond. – Everyone – 2016-12-05T18:40:31.390

Do you have an opportunity to run the host in a different run level, without running X? Depending on what access you have to the host, and what you want it to do, you could run it for a day or so without the GUI. If it also hangs, then you know that the issue is not about X. The telinit command can change run levels. – StandardEyre – 2016-12-07T20:57:35.840

Answers

1

I would look at /var/log/Xorg.0.log for errors first, before syslog, when debugging an X Windows issue.

From LinuxLogFiles

X11 Server Log

The default X11 Windowing Server in use with Ubuntu is the Xorg X11 
server, and assuming your computer has only one display defined, it 
stores log messages in the file /var/log/Xorg.0.log. This log is 
helpful for diagnosing issues with your X11 environment.

As I write this, I'm on a Ubuntu 14.04 system, and I don't have access to my Ubuntu 16.04 system. As far as I may tell, the logs are in the same place.

StandardEyre

Posted 2016-12-05T14:36:58.453

Reputation: 348

Thank you for the reference. Xorg.0.log doesn't list any errors per se but there may be a clue in that it recognizes my ps2 mouse as a trackpad device. I could be wrong though ... – Everyone – 2016-12-13T09:35:51.377

Asked: 2016-12-05T14:36:58.453

Viewed: 775 times

Active: 2016-12-13T09:33:22.157