I am running an Ubuntu instance on VirtualBox inside XP. Here are the details:

Host: Windows XP Pro
Guest: Ubuntu 8.10
Total RAM: 3GB
Total Video Memory: 128MB
Video Memory for VM: 40MB
Hard Drive: 200GB
Hard Drive for VM: 30GB
Processor: 2.80GHz Core Duo

The problem is that whenever I am inside the virtual machine, things seem so much slower in general. For example Firefox, Eclipse take longer to load, dragging windows show a lag etc.

I have tried running Ubuntu before (not inside a VM) and it seemed fantastically fast. So I am disappointed to have to deal with this situation. But I need access to the XP partition without having to reboot and hence the attempt.

I am surprised with the perceived slowness since the whole world seems to be doing virtualization and I cannot imagine everyone works on slow systems knowingly.

My question is - is there something I should be doing to boost performance? Am I doing something wrong?

This is my home machine and I am not sure if this is the right forum to ask. Thanks.

  • The standard release of Ubuntu used to not boot in VirtualBox due to VirtualBox not liking the kernel - I think the problem was with the kernel's ACPI support. You used to have to boot off the install CD image again, "repair" your fresh install and apt-get a new kernel. Does the kernel in the new release now support ACPI, or have they simply turned support off when running as a VM to avoid the problem? Would that be affecting performance? May 6 '09 at 22:55

There are a couple of things you can do.

  • Reduce the memory you give to the VM to half your total system memory or less. If the host doesn't have enough memory to operate smoothly, it will affect the guest. Typically Windows needs more memory and Linux needs less.
  • Enable VT extensions in the VBox settings. This uses hardware support built into your CPU if you have it available.
  • Turn off desktop effects like Compiz in the VM guest. VBox 2.2.2 has support for 3D acceleration in VMs, but 3D still slows things down a little.

I hope this helps.

EDIT: Another thing you can do is run top in a terminal window in the VM and see if there's a particular process eating the CPU or memory.
Does Windows get slowed down when you have issues with the VM?

  • @Magus - Reduced memory for guest to 1GB and I think I a slight improvement. I was already doing the other 2 things.
    – Kapsh
    May 5 '09 at 13:47
  • Look at your system and see if you are out of ram ... you can reduce the ram even further to the linux system if needed
    – trent
    May 5 '09 at 14:06
  • I do not seem to have problems on the host machine. top shows that eclipse takes up about 50% of my memory on guest, but apart from that there is no real hog there.
    – Kapsh
    May 5 '09 at 17:58

Have you installed Additions? They make quite a difference.

Here's how.

  • @vartec I do have Additions installed.
    – Kapsh
    May 5 '09 at 17:57
  • strange, I've got Kubuntu installed in Vbox with Additions and it's surprisingly fast. My setup is pretty much the same, except the processor is Core 2 Duo, and system is Vista (32-bit).
    – vartec
    May 5 '09 at 20:19
  • What kind of applications do you run inside Kubuntu?
    – Kapsh
    May 6 '09 at 13:23
  • Browsers (Firefox, Konqueror), IDE (Komodo), Apache server, etc.
    – vartec
    May 6 '09 at 14:38
  • "In VirtualBox, click Devices->Install Guest Additions" That would be cool. If VirtualBox even had a Devices menu.
    – TelFiRE
    Jun 2 '19 at 6:12

If this "...But I need access to the XP partition without having to reboot and hence the attempt..." is your REAL problem, then you can mount ntfs partions directly from Ubuntu(linux) with no problem. A quick google for "ubuntu ntfs" will give more details


I ran across a note somewhere about keeping the video memory assigned to a VM as a binary power for best performance. Try dropping to 32MB or bumping up to 64MB for your VM.


I had this problem too. I spent many hours playing with my xorg.conf. It appears to me that for my hardware anyway (Lenovo T60, ati video card), I can't use Mouse Integration or the vbvideo driver if I want to see reasonable performance. Try using your normal video driver instead. Another annoyance I have is that I can't do that neat dynamic window resize thing.


I've got the same issue with Ubuntu Server 9 under VirtualBox.

I use VB to test Weblogic Server (WLS) deployment scripts. Thus, I have to run a Weblogic admin server instance within the VM. Now, the startup time of the WLS is VASTLY uneven. Sometimes it starts in less than 2 minutes (OK for non-VM WLS), sometimes hangs on specific steps and apparently doing nothing (no disk or CPU activity detected).

The interesting fact though is that if the VB gets my keyboard input (i.e. I'm doing something in another console of the same Ubuntu), then startup is much faster. Often a simple "Enter" in the hanged WLS unix console wakes it up and it continues. Thus I think the problem is resource (CPU quants?) starvation. The VM is somehow gets a very low priority from Windows, and WLS has not enough CPU to execute. Well, it's just my idea.

What I'm really interested is how to fix it.

I have tried to give VB "High" or even "Real-time" priority in Windows Task Manager. The most visible result was VB hanged my machine while still failing to complete WLS boot in reasonable time. I'm open to any suggestion, really. If someone tells me "I do the same (run WLS) in VB under Slackware Linux" -- I'll install Slackware, no problem!

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