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I am sure the answers are out there, but alas there are too many answers (here and elsewhere) to other questions stopping me from finding them. I just encountered something substantially similar to what is described at the closed SO question, sudo : “segmentation fault” Ubuntu maverick [closed].

My team is using Ubuntu 11.04 on VMWare Workstation 8.0.4. We are doing development using c++, Xenomai, Qt, and Qt Creator. When we simulate our application on the virtual machine, we currently need to launch Qt Creator with sudo. My colleague mentioned today that he has been having issues where his workstation locks up and he needs to restart and that occasionally he has the issue that all sudo bash commands return "segmentation fault".

I just ran our application in simulation mode. I was running Qt Creator under sudo and Qt Creator received the signal abort (if I recall). Afterward, every command executed with sudo from sudo qtcreator to sudo ls resulted in the message Segmentation fault. I clicked on the power widget to see if I could log out, but the system shut down straightaway without prompting.

My understanding is that we run sudo because of a permissions issue with Xenomai and the VM as currently configured, but my colleague has a workaround for this. I expect that not running Qt Creator under sudo -- something that has always made me nervous -- will help contain this issue, but I find it troubling that this could happen and manifest as it does.

Does anyone know what is happening? Any recommendations on how to work around this issue?

This is happening often to I am trying tolobby for VM changes to be able to run the process without sudo.

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Do you have similar issues with Ubuntu 12.04 LTS? – david6 Oct 17 '12 at 7:17
Unfortunately @david6, the virtual machine is a controlled development environment so I am stuck with 11.04 until the team upgrades. I can try exploring this when I get some free time, but then I would still need to convince them to upgrade. There are other parts of our system that might also benefit from upgrades... – sage Oct 17 '12 at 15:44
I am near having a second machine set up with 12.04 and will report back. – sage Nov 1 '12 at 23:06

There is not a single answer to this problem other than it has probably to do with lack of memory. Try to see what free -m outputs and go from there. Adding swap space might solve the problem if you don't have enough.

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free -m indicates lots of free memory, but it is theoretically possible that the problem that messes up the system triggers the kernel to terminate a process that frees up memory. There is lots of SWAP (10+ GB), but I don't know how to check if I am running out of pages and I do not know how much of the memory 32 bit Ubuntu can address. – sage Nov 1 '12 at 23:04

Check for oom's in dmesg, the VM might have run out of memory. Almost all the time problems with such symptoms are somehow related to memory problems

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I will look for this as soon as I can get back to this task - thanks! – sage Oct 23 '12 at 18:21
I looked for oom's, but did not see anything. I searched for "oom", "OOM" and "memory". "memory" returned a number of hits, but nothing that looked like it was out of memory. – sage Nov 1 '12 at 23:05

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