Adding additional CPU fails without error

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Adding additional CPU fails without error

Postby Mitchellmitchellmitchell » 9. Aug 2019, 11:31

I have a headless Ubuntu host running a headless Ubuntu guest.

The guest was initially configured with 1 CPU. I tried to add CPU's using the following commands
Code: Select all   Expand viewCollapse view
VBoxManage modifyvm "VM name" --cpuhotplug on
VBoxManage modifyvm "VM name" --cpus 4
VBoxManage modifyvm "VM name" --plugcpu 1
VBoxManage modifyvm "VM name" --plugcpu 2
VBoxManage modifyvm "VM name" --plugcpu 3

None of this returned any errors. Then, loggin into my host I see nothing has changed. top, htop and lshw all show only one cpu. I'm not sure what I'm doing wrong and how to debug this issue.
Mitchellmitchellmitchell
 
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Re: Adding additional CPU fails without error

Postby socratis » 14. Aug 2019, 12:20

Does your Ubuntu guest even support CPU hot-plugging? And which Ubuntu are we talking about, 8.04, 16.10, 19.04? You got to give some more details about the setup.
If you obfuscate any information requested, I will obfuscate my response. These are virtual UUIDs, not real ones.
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Re: Adding additional CPU fails without error

Postby Mitchellmitchellmitchell » 21. Oct 2019, 14:13

Let it be said I am entirely unfamiliar with hardware and understand next to nothing about CPUs and computers. I'll try to add all required information, but a lot will probably be missing. Please bear with me.

The HOST is an Ubuntu 14.04.6 system, with 4 Intel(R) Xeon(R) Gold 6148 CPU @ 2.40GHz cores. According to HTOP the system has 16gb of memory.
I am using virtualboxmanage 4.3.40, which is (as I understand it) the last version for this old Ubuntu 14 system.

The guest is running Ubuntu 12. It's all really old but upgrading it is outside of my control. Below is the showvminfo for this VM
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name:            Ubuntu 12
Groups:          /
Guest OS:        Other/Unknown
UUID:            c48af8ae-6058-463e-a671-f1f567e83d6e
Config file:     /data_nfs/VM/Ubuntu 12/Ubuntu 12.vbox
Snapshot folder: /data_nfs/VM/Ubuntu 12/Snapshots
Log folder:      /data_nfs/VM/Ubuntu 12/Logs
Hardware UUID:   c48af8ae-6058-463e-a671-f1f567e83d6e
Memory size:     8192MB
Page Fusion:     off
VRAM size:       8MB
CPU exec cap:    100%
HPET:            off
Chipset:         piix3
Firmware:        BIOS
Number of CPUs:  4
PAE:             on
Long Mode:       on
Synthetic CPU:   off
CPUID overrides: None
Boot menu mode:  message and menu
Boot Device (1): DVD
Boot Device (2): DVD
Boot Device (3): HardDisk
Boot Device (4): Not Assigned
ACPI:            on
IOAPIC:          off
Time offset:     0ms
RTC:             local time
Hardw. virt.ext: on
Nested Paging:   on
Large Pages:     off
VT-x VPID:       on
VT-x unr. exec.: on
State:           running (since 2019-09-23T09:34:43.084000000)
Monitor count:   1
3D Acceleration: off
2D Video Acceleration: off
Teleporter Enabled: off
Teleporter Port: 0
Teleporter Address:
Teleporter Password:
Tracing Enabled: off
Allow Tracing to Access VM: off
Tracing Configuration:
Autostart Enabled: off
Autostart Delay: 0
Default Frontend:
Storage Controller Name (0):            IDE_12
Storage Controller Type (0):            PIIX4
Storage Controller Instance Number (0): 0
Storage Controller Max Port Count (0):  2
Storage Controller Port Count (0):      2
Storage Controller Bootable (0):        on
IDE_12 (0, 0): /data_nfs/VM/Ubuntu 12/Snapshots/{5f697831-a8a8-4e8b-8f06-c3e57365ea71}.vdi (UUID: 5f697831-a8a8-4e8b-8f06-c3e57365ea71)
IDE_12 (0, 1): /usr/share/virtualbox/VBoxGuestAdditions.iso (UUID: 959664fb-b1f2-4991-b241-6a71d282f5c4)
IDE_12 (1, 0): /data_nfs/VM/Ubuntu 12/Snapshots/{a9626dfd-6ea5-4859-b761-bda84f3913a6}.vdi (UUID: a9626dfd-6ea5-4859-b761-bda84f3913a6)
NIC 1:           MAC: 080027DF6EA8, Attachment: NAT, Cable connected: on, Trace: off (file: none), Type: Am79C973, Reported speed: 0 Mbps, Boot priority: 0, Promisc Policy: deny, Bandwidth group: none
NIC 1 Settings:  MTU: 0, Socket (send: 64, receive: 64), TCP Window (send:64, receive: 64)
NIC 1 Rule(0):   name = guest4433, protocol = tcp, host ip = , host port = 4433, guest ip = , guest port = 443
NIC 1 Rule(1):   name = guest80, protocol = tcp, host ip = , host port = 8080, guest ip = , guest port = 80
NIC 1 Rule(2):   name = guestftp, protocol = tcp, host ip = , host port = 2233, guest ip = , guest port = 2200
NIC 1 Rule(3):   name = guestssh, protocol = tcp, host ip = , host port = 2222, guest ip = , guest port = 22
NIC 1 Rule(4):   name = jupyterhost, protocol = tcp, host ip = , host port = 8889, guest ip = , guest port = 8889
NIC 2:           disabled
NIC 3:           disabled
NIC 4:           disabled
NIC 5:           disabled
NIC 6:           disabled
NIC 7:           disabled
NIC 8:           disabled
Pointing Device: PS/2 Mouse
Keyboard Device: PS/2 Keyboard
UART 1:          disabled
UART 2:          disabled
LPT 1:           disabled
LPT 2:           disabled
Audio:           disabled
Clipboard Mode:  disabled
Drag'n'drop Mode: disabled
Video mode:      640x480x32 at 0,0
VRDE:            disabled
USB:             disabled
EHCI:            disabled

USB Device Filters:

<none>

Available remote USB devices:

<none>

Currently Attached USB Devices:

<none>

Bandwidth groups:  <none>

Shared folders:  <none>

VRDE Connection:    not active
Clients so far:     0

Video capturing:    not active
Capture screens:    0
Capture file:       /data_nfs/VM/Ubuntu 12/Ubuntu 12.webm
Capture dimensions: 1024x768
Capture rate:       512 kbps
Capture FPS:        25

Guest:

Configured memory balloon size:      0 MB
OS type:                             Linux26_64
Additions run level:                 2
Additions version:                   4.3.40 r110317


Guest Facilities:

Facility "VirtualBox Base Driver": active/running (last update: 2019/09/23 09:34:56 UTC)
Facility "VirtualBox System Service": active/running (last update: 2019/09/24 08:14:48 UTC)
Facility "Seamless Mode": not active (last update: 2019/09/24 08:14:48 UTC)
Facility "Graphics Mode": not active (last update: 2019/09/23 09:34:56 UTC)

Snapshots: increasing size (UUID: 472e5451-60a9-4ed4-8e59-f40b839b814c) *

As can be seen the number of CPUs is set to 4. As far as I understand the documentation (which I barely understand. Most of it is explained at a level I don't understand (i.e. I don't know anything about computers).

When running the guest however, if I open /proc/cpuinfo, it shows me only one time Intel(R) Xeon(R) Gold 6148 CPU @ 2.40GHz. I'm not sure if I'm doing something wrong with virtualbox, or if I need to somehow let the guest know it has more CPU now?

I'm unsure how to proceed.
Mitchellmitchellmitchell
 
Posts: 9
Joined: 9. Aug 2019, 11:25

Re: Adding additional CPU fails without error

Postby socratis » 21. Oct 2019, 15:26

Why exactly do you want to hot-plug a CPU? This is really advanced operations, not a lot of people have attempted it. What are you trying to "solve"?

We need to see a complete VBox.log, from a complete VM run, where the problem occurs:
  • Start the VM from cold-boot (not from a paused or saved state) / Observe or recreate the problem / Shutdown the VM (force close it if you have to).
  • With the VM completely shut down (not paused or saved), right-click on the VM in the VirtualBox Manager and select "Show Log".
  • Save only the first "VBox.log", ZIP it and attach it to your response. See the "Upload attachment" tab below the reply form.
Image
If you obfuscate any information requested, I will obfuscate my response. These are virtual UUIDs, not real ones.
Do NOT reply with the "QUOTE" button, please use the "POST REPLY", at the bottom of the form.
socratis
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Posts: 26059
Joined: 22. Oct 2010, 11:03
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VBox Version: PUEL
Guest OSses: Win(*>98), Linux*, OSX>10.5

Re: Adding additional CPU fails without error

Postby Mitchellmitchellmitchell » 21. Oct 2019, 17:38

My intention is simply to increase the CPU power (?) of the guest.

The guest can be switched on/off. I only have access to the host (and guest) over the command line.

I have attached a zip of the VBox.log.

There is not real error anywhere, since the guest just runs normally (but without the increased CPU that I'm trying to accomplish)
As such, the log is starting the vm, me opening /proc/cpuinfo and then shutting down the vm again.

I believe this is what you requested. I hope it helps :)
Attachments
VBox.rar
(16.98 KiB) Not downloaded yet
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