VirtualBox

Opened 13 years ago

Closed 13 years ago

Last modified 11 years ago

#8803 closed defect (worksforme)

VM does not recognize multicore CPU — at Version 7

Reported by: Giovanni Lelli Owned by:
Component: VMM Version: VirtualBox 4.0.6
Keywords: Multicore; CPU; linux Cc:
Guest type: Linux Host type: Windows

Description (last modified by Frank Mehnert)

The boot procedure hangs up when setting a number of CPUs higher than 1.

The host OS is Win7 SP1 Professional. The guest OS is Ubuntu 10.10.

Note: The virtual machine was created without specifying the number of CPUs (4 in my case) and does not give any problem (except for its slowness) if I use a single-CPU setting.

Change History (11)

by Giovanni Lelli, 13 years ago

Vbox.log

comment:1 by Frank Mehnert, 13 years ago

Where does the guest boot hang? Please

  1. Enable the 1st serial device for that VM and attach it to a host file.
  2. Boot the guest into GRUB and edit the kernel command line.
  3. Remove quiet splash
  4. Add ignore_loglevel console=ttyS0

Then boot the guest and attach the resulting file with the serial output to this ticket.

in reply to:  1 comment:2 by Giovanni Lelli, 13 years ago

Replying to frank:

Where does the guest boot hang? Please

  1. Enable the 1st serial device for that VM and attach it to a host file.
  2. Boot the guest into GRUB and edit the kernel command line.
  3. Remove quiet splash
  4. Add ignore_loglevel console=ttyS0

Then boot the guest and attach the resulting file with the serial output to this ticket.

Hi Frank,

The VM does not even start if I set more than 1 CPU. I've uploaded a new log file, together with a screen capture.

Could you please suggest me also how to boot the guest into GRUB?

Many thanks,

Giovanni

by Giovanni Lelli, 13 years ago

Vbox.log (update)

by Giovanni Lelli, 13 years ago

Attachment: Print screen.doc added

Screen capture

comment:3 by Frank Mehnert, 13 years ago

Ah! The problem is that the VT-x extension of you host computer is disabled. Reboot your host, go into the BIOS and search for a setting virtualization technology or something like that -- enable that setting. Sometimes a BIOS upgrade is necessary.

in reply to:  3 comment:4 by Giovanni Lelli, 13 years ago

Replying to frank:

Ah! The problem is that the VT-x extension of you host computer is disabled. Reboot your host, go into the BIOS and search for a setting virtualization technology or something like that -- enable that setting. Sometimes a BIOS upgrade is necessary.

OK, great!

Now it works! Thank you very much!

Giovanni

comment:5 by Frank Mehnert, 13 years ago

Resolution: worksforme
Status: newclosed

comment:6 by JoseM11, 11 years ago

I am having a problem running on Virtual BOx on a windows OS 7 Enterprise. The guest OS is Ubuntu 10.10.

I have created the virtual machine without specifying the number of CPUS. Before I start the virtual machine I had changed the number of CPUS to 4. (my windows box has 4 CPUS and 8 virtual cpus). I have read the thread above and check that the BIOS had the VT-x enabled. In fact the settings for the virtual machine states that VT-x/AMD-V is enabled and also that Nested Paging is enabled.

My processor is Intel Core i7-3720QM

I have tried to run a very simple mpi program using that prints the number of tasks it believes it has

mpirun -np 2 a.out

and it reports that I have only 1 CPU and of course 1 tasks.

The above line appears to run in serial.

Not sure what or if I am doing something wrong.

How do I make mpi to realize that I have 4 cores. Not sure if this is a Virtual Box issue or an mpi issue.

Can anyone help?

by JoseM11, 11 years ago

Attachment: VBox.log added

comment:7 by Frank Mehnert, 11 years ago

Description: modified (diff)

Your VM has definitely 4 virtual CPUs running. Just use

cat /proc/cpuinfo

in the guest to verify that. Your mpi problem is something else and I suggest you to go to the forums (forums.virtualbox.org) to ask for help.

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