[solved] linux guest hangs at boot if more than 1 cpu is assigned to the vm

[masavini]

hi,
i'm running virtualbox 4.3.40 on a ubuntu 14.04 host (kernel is 3.13.0-141).

i can run a windows 8 guest using multiple cores with no problems.

when it comes to linux guests, however, if more than 1 cpu is assigned to the vm i can't even run the os installer: as soon as it boots, the screen goes black with a bliking cursor in the high left corner and all of the assigned cpu run at 100% until i terminate the vm.

what i tried so far:
- several different guests:
- manjaro 20
- ubuntu 20.04
- ubuntu 18.04
- reinstalled virtualbox
- reinstalled the kernel
- installed virtualbox 6.1

i have another machine with a similar setup (virtualbox 4.3.36 on a ubuntu 14.04 host kernel is 3.13.0-153) where i can run an ubuntu 20.04 vm with 4 cpus without any issue...

[masavini]

please find attached the logs of manjaro 20 installation iso running with 4 cpus (terminated while hanging) and 1 cpu (terminated while perfectly working)...

[masavini]

update: just tried to install virtualbox 5.2, same result...

[mpack]

VirtualBox VM 4.3.40_Ubuntu r110317 linux.amd64 (Mar 15 2019 12:33:50) release log

What you have there is not VirtualBox. What you have there is an ancient (support for 4.3.x official ended 5 years ago) third party build from the VirtualBox sources. So even if it was a genuine build it is no longer supported.

If you have a problem with a currently supported genuine install of VirtualBox then we'll be interested to see a log from that.

p.s. Please zip logs before attaching them.

[masavini]

i installed the genuine 5.2 version, but the problem persists...
please find the log attached.
thanks!

[mpack]

I don't see any problem with the VM - the VM runs fine until it is closed at user request after only 90 seconds. I would (a) leave it longer to be sure that it has actually hung, and then (b) investigate reasons why the Manjaro installer would hang during boot. For example the processor seems quite old (launched 8 years ago), so perhaps your problem lies with the version of Manjaro you're trying to install.

Also, what happens if you install the OS using one core, then close down and switch to 2 cores?

Also, apparantly Manjaro is based on Arch Linux, so why are you using the Ubuntu template instead of the Arch Linux template?

[Martin]

Black screen with a blinking cursor is often not a "hanging" guest, it's just a Linux guest which didn't manage to start its graphical interface.

[masavini]

I don't see any problem with the VM - the VM runs fine until it is closed at user request after only 90 seconds. I would (a) leave it longer to be sure that it has actually hung, and then (b) investigate reasons why the Ubuntu installer would hang during boot. For example the processor seems quite old (launched 8 years ago), so perhaps your problem lies with the version of Ubuntu you're trying to install.

Also, what happens if you install the OS using one core, then close down and switch to 2 cores?

I don't see any problem with the VM - the VM runs fine until it is closed at user request after only 90 seconds. I would (a) leave it longer to be sure that it has actually hung

i stopped it after 90 seconds because i had 4 cores running at 100% for the whole 90 seconds and they were becoming pretty hot... but i can ensure it's hanging: if i launch it with 1 cpu it takes about 20 seconds to enter the os installation...
i have another vm with ubuntu 20.04: with 1 cpu it takes about 5 seconds to start showing the boot process steps, and about 60 seconds to show the login menu. with more than 1 cpu, instead of showing the boot steps all of the cores go 100% and the screen is black with a fixed cursor in the upper left corner.

(b) investigate reasons why the Ubuntu installer would hang during boot. For example the processor seems quite old (launched 8 years ago), so perhaps your problem lies with the version of Ubuntu you're trying to install.

Also, what happens if you install the OS using one core, then close down and switch to 2 cores?

in the last couple of days i made A LOT of tests... these are the OSes i tried:
ubuntu 20.04 desktop
manjaro 20 kde
ubuntu 18.04 desktop
ubuntu 16.04 desktop
ubuntu 14.04 desktop

with all of those, the behavior is the same:
- with more than 1 cpu, when i boot the vm with the live-cd iso i can enter the boot menu, but as soon as i select the 'install' option i get a black screen with a fixed cursor in the upper left corner. all of the cores go 100% and nothing will happen except cooking my cpu.
- with 1 cpu i can install the os with no problems and also run it once installed. but if i add more cpu, a few seconds after the boot the cores will go 100%, black screen with cursor and nothing will happen except cooking my cpu.

there are just 2 exceptions to the examples above:
1) ubuntu 18.04 mini.iso -> i can complete the installation process (server or even full desktop) with more than 1 cpu, but the installed os only starts with 1 cpu
2) windows 8.1 -> tested with up to 4 cpu, no problems at all

Also, apparantly Manjaro is based on Arch Linux, so why are you using the Ubuntu template instead of the Arch Linux template?

my mistake while saving the log, but i can ensure the very same happened with arch64 selected as template. i think i tried something like 20 times...

[masavini]

Black screen with a blinking cursor is often not a "hanging" guest, it's just a Linux guest which didn't manage to start its graphical interface.

this is what i thought when i tested that i could install ubuntu 18.04 with 4 cpu using the mini.iso version (command line interface).
but the installed server only boots with 1 cpu, so... i just don't know...

[fth0]

00:01:31.591725 /TM/CPU/00/cNsExecuting          47633165111 ns
00:01:31.591737 /TM/CPU/00/cNsHalted              2480566695 ns
00:01:31.591744 /TM/CPU/00/cNsOther              39446804313 ns
00:01:31.591751 /TM/CPU/00/cNsTotal              89560536119 ns
00:01:31.591757 /TM/CPU/00/cPeriodsExecuting     68560203 count
00:01:31.591763 /TM/CPU/00/cPeriodsHalted             194 count
00:01:31.591787 /TM/CPU/00/pctExecuting                54 %
00:01:31.591794 /TM/CPU/00/pctHalted                    0 %
00:01:31.591800 /TM/CPU/00/pctOther                    45 %
00:01:31.591807 /TM/CPU/01/cNsExecuting          81650987835 ns
00:01:31.591813 /TM/CPU/01/cNsHalted              6099357686 ns
00:01:31.591820 /TM/CPU/01/cNsOther               1810256565 ns
00:01:31.591827 /TM/CPU/01/cNsTotal              89560602086 ns
00:01:31.591834 /TM/CPU/01/cPeriodsExecuting      2750954 count
00:01:31.591857 /TM/CPU/01/cPeriodsHalted              20 count
00:01:31.591863 /TM/CPU/01/pctExecuting                98 %
00:01:31.591869 /TM/CPU/01/pctHalted                    0 %
00:01:31.591875 /TM/CPU/01/pctOther                     1 %
00:01:31.591881 /TM/CPU/pctExecuting                   76 %
00:01:31.591886 /TM/CPU/pctHalted                       0 %
00:01:31.591892 /TM/CPU/pctOther                       23 %

The VBox.log files confirm that the 2nd CPU core Is nearly continuously running. I suspect a problem when the guest is initializing the additional CPU core(s), but have no good idea how to solve this (except by using a newer CPU, newer Linux kernels in host and guest, and a current VirtualBox version).

Maybe I found something: Set System > Acceleration > Paravirtualization Interface to Default or KVM.

[masavini]

a new test...
i booted my pc with ubuntu-desktop-14.04 live usb, then installed virtualbox-5.2, created a vm with 2 cpu and booted ubuntu-14.04.6-desktop-amd64.iso... it works perfectly...



i guess this demonstrates that the problem i'm facing is not related with the host cpu or kernel age... it must be something in my virtualbox configuration: how can i completely purge it and perform a clean virtualbox installation?

[masavini]

solved, finally!

i performed another test, booting my laptop with the oldest ubuntu 14.04 desktop version i could find: ubuntu-14.04.1-desktop-amd64 (kernel 3.13.0-32).
in the live usb system i installed virtualbox-5.2, i created a new vm with 2 cpu and started it with manjaro-kde-20.0.1-minimal-200511-linux56.iso: perfectly working, as i expected.

at this point it was clear that my issue wasn't caused by the cpu, the kernel or anything related with the host: it was a virtualbox configuration problem.

here is what i did, then:
1) purged virtualbox:

Code: Select all

$ sudo apt purge virtualbox*
[...]
dpkg: warning: while removing virtualbox, directory '/usr/lib/virtualbox/ExtensionPacks' not empty so not removed
$ sudo rm -r /usr/lib/virtualbox

2) installed virtualbox-5.2_5.2.40-137108~Ubuntu~trusty_amd64.deb using ubuntu software center, and then installed the extension pack

the virtual machines with linux guests i created with the previous virtualbox version still didn't boot with more than 1 cpu, but the new ones do.

thanks for your help!