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Hello all. My Ubuntu 11.10 installation seems to suddenly lock up. I cannot move my mouse or use the keyboard, all screen activity stops, and I have to do a hard reboot. Is there an y method to repair this? It started a few days ago.

nanofarad
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Alen
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1 Answers1

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Before you panic, try the magic SysRq trick. Find the key on your keyboard labelled PRT SCRN|SYSRQ(Could be arranged differently). Hold that key, ALT and M. This invokes the Linux oom_kill which could aid in recovering. Also, try this with B instead of M and see it it reboots then. If it does, then you are either out of memory(If you have a swap partition, your disk may be active), or you have another software issue. If not, it is hardware. Try pressing CTRL+ALT+F1 during the freeze. Does that work? If so, you can use top after logging in to ascertain the process causing the issue.

Try running vmstat 1 in the Teminal. In a comment, tell us your swapin and swapout values.

Also ,try running top, giving us the top %CPU values, then pressing SHIFT+O, then Q or T, then ENTER. and the RSS and SHR values of the top processes. This can help pinpoint the cause. Also, are you using Skype, by any chance? There is a reported memory leak in it.

nanofarad
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  • I followed your first instruction and the only thing my OS did was it captured the screen couple of times – Alen Jun 11 '12 at 20:48
  • swapin 0 swapout 1484, that's the min and max values.

    top - 23:02:36 up 10 min, 1 user, load average: 1.64, 1.76, 1.20 Tasks: 155 total, 3 running, 152 sleeping, 0 stopped, 0 zombie Cpu(s): 4.0%us, 2.2%sy, 0.0%ni, 92.9%id, 0.7%wa, 0.0%hi, 0.3%si, 0.0%st Mem: 993648k total, 895432k used, 98216k free, 89128k buffers Swap: 1013756k total, 11072k used, 1002684k free, 190168k cached

    – Alen Jun 11 '12 at 21:02
  • I have skype installed but not using it – Alen Jun 11 '12 at 21:03
  • did I provide you with all information you need? – Alen Jun 11 '12 at 21:44
  • Were you holding ALT when tried to use the key combo? Or do you have a separate SysRQ key? Also, is the info about memory from after the lockup or before(using the terminal given with ctrl +alt+F1)? Were you able to switch to a terminal using that key combo? – nanofarad Jun 11 '12 at 22:16
  • Is Skype set to auto-start and auto-login? This could be very important. – nanofarad Jun 11 '12 at 22:16
  • yes, I was holding all that keys you mentioned. When I pressed ctrl+alt+f1 I was taken to root but I didn't know how to switch back to desktop so I rebooted PC. skype is not set on auto-start. – Alen Jun 12 '12 at 08:45
  • it happend again today, but I couldn't do anything, couldn't even turn off the num lock light on keyboard – Alen Jun 12 '12 at 16:53
  • What kind of CPU do you use? Can you do a memtest from the correct choice in Grub(Main pre-boot menu) – nanofarad Jun 12 '12 at 17:42
  • CPU is Pentium 4 2.8 GHz. I will report you as soon as I make memtest – Alen Jun 12 '12 at 18:17
  • memtest reported some errors, maybe that' why it's freezing – Alen Jun 12 '12 at 19:58
  • You'll need to tell me where the error is and I will show you how to add badram info to Grub. – nanofarad Jun 12 '12 at 20:03