virtualbox.org

Turning off nested paging allows me to have a stable guest with as many cores as I want...
So, I can either have nested paging with 2 virtual cores or no nested paging with 8 cores.

Indeed, disabling nested paging did the trick for me... no more loooong boot times, no matter if I set 1 or 3 or 4 cores, it's ok now. Thanks, elirov

Edit: Not really... it's doing it again

Check this out:
http://serverfault.com/questions/35918/ ... virtualbox

I tried adding divider=10 to grub and it does seem to make things a bit faster, except the UI is less snappy. Also, my host won't go to sleep anymore...

elirov wrote:I tried adding divider=10 to grub

you are doing this to a Ubuntu kernel?

divider=10 is a cure for the 1000Hz interrupt timer RedHat/Fedora kernels, while Ubuntu kernels are running the timer at 100Hz or 250Hz IIRC

This bug is stil in version 4.0.2. Workround for me is starting Ubuntu on guest with acpi=off. Then it works fine even I have assigned 8 processors to guest.

ACPI=off didn't work for me, Ubuntu wouldn't even boot. But setting the processors to 2 seems to work. I've had a Windows 7 guest lock up the same way on occasion and had to change the processors to 2 in order to fix it. This is really a problem.

I have also experienced this issue with all versions up through to 4.0.4. I have been running Arch linux and Kubuntu in varieties of 64 and 32 bit, with dynamic storage. Arch linux was stable with one cpu, but incredibly unstable to locking up with more than 1 (i.e. freezes within minutes). I have found Kubuntu to be relatively stable (i.e. crashes once a day on average) when used with more than one core (usually 4). It frequently crashes when I access network storage (I have a workstation I ssh into) heavily, for music etc (random access coincides with crashes, but fixed file transfer back and forth is more stable). I have run this system for a couple of days doing multicpu (100% cpu usage) computation a number of times and this does not cause it to freeze. However, simple usage of a browser and text editor can cause a freeze. I often use a 3g wifi router for internet which randomly resets. My suspicion is that the freezing is related somehow to network access.

Is there a solution for this problem?

add "nolapic_timer" to kernel line may solve this. it does work on mine. have a try~

RONSMEYER wrote:ACPI=off didn't work for me, Ubuntu wouldn't even boot. But setting the processors to 2 seems to work. I've had a Windows 7 guest lock up the same way on occasion and had to change the processors to 2 in order to fix it. This is really a problem.

I have an Ubuntu 10.10 64-bit guest running on a Windows 7 64-bit host. Lowering the number of processors from 4 to 2 solved my freezing issues, which were random but mostly occurred when running an IDE.

I was having this issue as well, and after changing the no-acpi setting, everything was going well until last night. I don't remember doing anything major yesterday on the system, so nothing stands out in my mind that could be a direct cause. I did update to newest Linux kernel earlier in the week, but haven't had any issues with the system in between. I came back to my desk this morning to find my guest completely frozen, and a reset brought me to the Ubuntu loading screen with absolutely not disk activity afterwards. The only way I have been able to get the system up and running again is to drop back down to 1 CPU again

tiembo wrote:

RONSMEYER wrote:ACPI=off didn't work for me, Ubuntu wouldn't even boot. But setting the processors to 2 seems to work. I've had a Windows 7 guest lock up the same way on occasion and had to change the processors to 2 in order to fix it. This is really a problem.

I have an Ubuntu 10.10 64-bit guest running on a Windows 7 64-bit host. Lowering the number of processors from 4 to 2 solved my freezing issues, which were random but mostly occurred when running an IDE.

I tried running the guest with 3 processors, but it would randomly freeze within 24 of uptime. Back down to two for now.

I can confirm the same random freezes occur here on my system as well. Ubuntu 10.10 simply freezes and the guest window shows "Not Responding" on my Windows host. It will usually run anywhere between 1 hour and 48 hours before locking up. Here are the system details:

Host - AMD Phenom X4 9750 Quad Core CPU, 8GB RAM, 5TB total HD space, Windows 7 Home Premium 64-bit

Guest and settings - Ubuntu 10.10 Server 64-bit, 2 CPUs, AMD-V on, Nested Paging on, ACPI on, 512 MB RAM, 32 MB video, 64 GB HD

Per suggestions in this thread, I'm going to try shutting off Nested Paging first and see if that improves things. Beyond that, I'll be making one guest configuration change at a time until it becomes stable.

OK, so I made the change above (only turned off Nested Paging). The VM ran for about a day and a half. This morning I found an error window over the top of the VM window saying it had encountered a critical error. Instructions were that I could find what happened in the logs directory and a screenshot there as well. I could click OK to stop the VM or Ignore to debug. Attached is the log (in a ZIP file) and screenshot.

This VM is configured as a LAMP server, and it also has Ampache (note the "m") installed for streaming music to my phone. Nothing was running on it other than the background services which service Apache, Ampache, etc.

I change the number of CPUs to 1, and turned off ACPI. I restarted the VM, and will wait to see how long it runs.

Well, it ran for about a day, and then the same thing happened with the error window again. (Been delayed getting back on here to post about it.) So, now I'm not sure what to do to try to resolve this. Should I turn off the AMD-V acceleration? Should I change from using 64-bit to 32-bit Ubuntu guest OS?