Windows7 guest looses control

[Leopold47]

Hello, VirtualBox forum members,
I am new to this forum. I am running xp vista and windows 7 clients in an educational environment. We try to help senior – elderly people to use the computer. The idea of giving a (virtual) computer to every student brought us to VirtualBox. We recently started our courses with the new virtual machines. Most of the time it runs ok but every now and than the guest looses control. This is disturbing during the classes. Only a restart of the client or sometimes a restart of the host will help. When we tested Virtualbox we did not face these problems. I have Virtualbox 4.1.6, the extension pack en the guest additions installed on our Windows7 computers in the classroom. I disabled the hibernating on the host as well as on the guest. I have tried several suggestions on the forum, but it looks like I am doing something wrong. The logfile is from a virtual machine that has lost control. I 'd like to know why. Any suggestions?
Thanks, Leopold

[Perryg]

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00:00:01.279 Host RAM: 3071MB RAM, available: 2208MB
00:00:03.474   RamSize         <integer> = 0x000000005d700000 (1567621120)

Typically not a good idea to allocate more than 50% of the available RAM to the guest

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00:00:04.261 Audio: Trying driver 'dsound'.
00:00:04.351 DSound: Could not initialize DirectSoundCapture
00:00:04.353 HDAcodec: can't open in fmt(freq: 44100)
00:00:04.355 HDAcodec: can't open out fmt(freq: 44100)
00:00:04.355 HDA: WARNING: Unable to open PCM IN!
00:00:04.355 VM: Raising runtime error 'HostAudioNotResponding' (fFlags=0x0)
00:00:04.355 Console: VM runtime error: fatal=false, errorID=HostAudioNotResponding message="Some audio devices (PCM_in) could not be opened. Guest applications generating audio output or depending on audio input may hang. Make sure your host audio device is working properly. Check the logfile for error messages of the audio subsystem"

I would see what the issue is and see about fixing or disable the sound.

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00:28:06.857 ERROR [COM]: aRC=VBOX_E_IPRT_ERROR (0x80bb0005) aIID={09eed313-cd56-4d06-bd56-fac0f716b5dd} aComponent={Display} aText={Could not take a screenshot (VERR_NO_MEMORY)}, preserve=false

This warning is due to the preview screen in the VirtualBox main manager. You can disable the preview update and stop this. But the error VERR_NO_MEMORY sounds like you have exhausted the memory on the host or possibly the guest, which would cause your issue. Still may be due to the memory of the guest being set to high. Try 1024MB and see if it helps.

[Leopold47]

Hi Perryg,

Thank you for your advise.
I was not aware that the amount of memory of the guest may not exceed 49% of the available ram.
Available ram apparently is the amount of memory in the host minus the memory used by the operating system of the host.
Anyway it solved my problem.


Keep up the good work.
Thanks again.
Leopold