virtualbox.org

Hi. Today VirtualBox crashed, which in my experience is uncommon to begin with, but there was also something I've never seen, as best I can recall: a dialog box with a man sitting cross-legged, I think it was, and the words "Guru Meditation", advising me to come here for help. Since some people I trust have advised me to meditate more, I figured I should do as the Guru suggests. So here I am. :-)

I've searched the forums; read The Forum Posting Guide, VirtualBox FAQ and User_FAQ on the main site; and reviewed the Troubleshooting section of the user manual. Here, with a couple of additional headings I think are relevant, is the information the user FAQ directs me to provide:

Environment:

• Version of VirtualBox installed:

4.1.22-80657~Ubuntu~quantal

[*]Type and version of the Host Operating System:

Kubuntu 12.10

[*]Type and version of the Guest OS:

Windows Vista (fully updated)
[*]Version of Guest Additions installed: the version that came with the package above[/list]

Problem:

• What I was doing when the problem occurred?
  
  I was working in my Windows guest with a regular (non-admin) Windows user account. I opened the Windows hosts file as an administrator; and I edited it to add lines for several machines on my local network, for which I recently made DHCP reservations in my wireless router. (I've got the Vista guest using bridged networking.) Then I installed the NetDrive drive-mapping utility so I could manage files on other machines, both within and outside my local network, as if they were on the Vista virtual machine, via WebDAV and SFTP. To reach a web server with some page templates I have to edit, I needed a line from the hosts file of the Linux machine on which I run VirtualBox. I tried NetDrive for the first time by connecting from within the Vista guest to the Linux host by SFTP. Everything was fine as far as I remember. I switched Windows user accounts to check whether another user could access the mapped drive. (Unfortunately, it could.) Apparently I also opened NetDrive and I switched back to the first Windows user account, disconnected NetDrive and I'm pretty sure exited it. I think I had just switched Windows user accounts back to the second one, which is an admin account, when the crash occurred. I did not log out of the first user account either time.
  
  Apparently at some point I also connected NetDrive to the Linux machine from the second, admin account as well, because the automatic screen shot VirtualBox took just before the crash (see below) shows it. I don't remember if I did this the first time I logged in with the admin account or the second time.

• What did you expect and what was the result?

I expected VirtualBox and Vista to keep running. The result was a crash, with a dialog labeled Guru Meditation, advising me to get help from the Community section of http://www.virtualbox.org.

[*]What are you trying to accomplish

now?

Identify the cause, or likely cause, of this crash so I can avoid doing it again, and I hope make the remaining Windows hosts file modification and use NetDrive.[/list]

Attempted Resolutions:

• Have you searched the User Manual?

Yes

[*]What have you attempted and what was the result of each attempt?

I have not yet tried again to use the machine that crashed.[/list]

Log files:

• If you are reporting a problem on the bug tracker or in the forums (please do not post log files to a mailing list unless you are asked to!) you should provide any relevant log files.

Attached. The board imposes a 128 KB limit on attachments, so I had to break VBox.log file into three parts. It also imposes a limit of three files, so I'll try to post a comment with the screen shot.

[*]If you were able to start a virtual machine at all, please provide the most relevant log file from a machine which you ran, as it contains lots of useful information!

I'm not clear on the difference between this item and the previous one. If you need any other log files, please let me know.

[*]If you had an installation problem, please provide any installation log files (different systems have them in different places).

Not applicable

[*]If your problem is about graphics in a Linux or Solaris guest, please include a relevant X server log.

Not applicable[/list]

Thanks for any help anyone can provide, and if there's any other information from me that would be helpful, please let me know.

<mod edit> Replaced uncompressed log file parts 1, 2 and 3 with a single .zip.

Here's the screen shot. As with the log file, the 128 KiB limit prevents me from attaching the original. (Indexing to 256 colors gives sharper text than a JPG would, at the expense of a crappier background.)

For future reference: zip up your logs, that saves space and makes it easier for us to browse. PNG is a good graphics choice, probably reducing the color count was not necessary - PNG compression is quite good on graphics.

As to your crash, it is this one :-

VBox.log wrote: 04:34:03.852 !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
04:34:03.852 !!
04:34:03.852 !! Guru Meditation -2701 (VERR_VMM_RING0_ASSERTION)
04:34:03.921 !!
04:34:03.921 VMMRZCallRing3: enmOperation=9 uArg=0x0 idCpu=0x0
04:34:03.921
04:34:03.921 !! TRAP=0d ERRCD=0000000000000000 CR2=000000008013d066 EIP=8a5b9dd4 Type=0
04:34:03.921 !! EIP in VMMGC.gc (8a5b2000) at rva 7dd4 near symbols:
04:34:03.921 !! 8a5b9d00 rva 00007d00 off 000000d4 VMMRZCallRing3
04:34:03.921 !! 8a5b9df0 rva 00007df0 off -0000001c VMMRZCallRing3NoCpu
04:34:03.932 !! fff8:8a5b9dd4 8b 83 e4 2f 00 00 mov eax, dword [ebx+000002fe4h]
04:34:03.932 !!

Unfortunately I've never heard a satisfactory explanation of "RING0 ASSERTION" crashes. I mean I know what the words mean, but I don't see a pattern for what triggers it. In the past it has been worked around by reducing the RAM allocation of the VM, but your allocation does not seem excessive, in fact is close to what I would consider ideal (i.e. around half the hosts available RAM, about a third of the total). Does your host support VT-x? If so I would try turning that on.

Thanks for the speedy reply, mpack. An urgent, important situation erupted shortly after our initial posts and sucked up all my personal bandwidth; but things are getting back to normal now. I don't know why it didn't occur to me to zip up the logs. By then my brain must've been fried trying to solve the harder problem. The screenshot VirtualBox saved automatically was a PNG, and it was well over 300 MB. But yeah, I just did a bit of testing, and probably I could've gotten it down to half that size simply by exporting the RGB version from GIMP with maximum compression.

As to the crash: The host is a Toshiba Satellite A135-S4427, with Intel® Core™ Duo Processor T2250. I checked Intel's online product information. Unfortunately, this processor does not support VT-x.

If there's anything else you can think of that I should try, please let me know. Otherwise I'll probably try to make it crash again and report what happens. Thanks again for the help!