I'm trying to install Debian on VirtualBox running on a Debian host, but the guest is incredibly slow. Looking at the output of top it appears that the guest is CPU bound (I see high CPU usage but very low disk wait and no swapping).

Why could this be?

Stats are:

  • Debian 6 (both host and guest)
  • VirtualBox-ose installed from Debian repos (version 3.2.10 edit I've since upgrade to 4.1.2 binaries from virtualbox.org and I'm still having the same issues).
  • Host CPU info: http://paste.pocoo.org/show/491839/
  • Guest has ~300 megs of RAM, which should be plenty for the non-graphical installer
  • The install has been running for close to three hours now, and it seems to be spending most of its time on the "configuring package" steps

Edit: I've installed VirtualBox onto an identical host running Windows XP and everything is fast (or, at least, as fast as it should be)… So this would appear to be an issue with VirtualBox + Linux or Debian.

  • Have you looked at what top of guest sez?
    – tshepang
    Oct 14, 2011 at 9:48
  • he's still at the install stage... top doesn't work yet.
    – lornix
    Oct 14, 2011 at 23:07

1 Answer 1


You'd be better off ditching the -OSE version and getting the REAL version from the virtualbox.org website, as the -OSE 'trial' doesn't allow USB to be used, and there may be other issues too. Just avoid it. (The virtualbox.org current version is 4.1.4, so you're woefully behind using the 3.2.10 -OSE version)

VirtualBox has debian repositories available, look at the linux downloads section for information on what to add for access to the repos.

Of course, you could download the 'all distributions' version and install it as root, although you won't get automatic updates unless you use the debian repo method (you'd have to update yourself manually each time)

Be aware you need to ALSO download the 'extension pack' (found on their 'downloads' page) to enable USB 2.0 and certain machine enhancements.

Your /proc/cpuinfo shows a decent 2.8Ghz Intel processor, so speed issues would depend heavily on how much memory the HOST system currently has, how loaded it is. Your 300M for the guest is fine, as long as you're not installing the Xwindows functionality.

Are your 'virtual hard disks' preallocated or 'grow on use'? 'grow' is slower, but not that much slower, shouldn't be a big difference there. Are the virtual HD's located on an external drive? That'll slow any disk accesses down considerably.

Mostly, in this case, I'd question how much memory the HOST has, what all is running currently (in addition to VBox), and possibly the -OSE version, as it may not be optimized for speed.

  • Since asking, I have updated to the current 4.1.4 binary from virtualbox.org… But unfortunately it looks like I'm still having the same sorts of issues. Oct 14, 2011 at 18:14
  • The disks are set to “grow”… But if that were my issue, I would expect to see a bit of disk I/O on the host… No? Oh well, maybe I'll try that later. Oct 14, 2011 at 18:15
  • How much RAM does the HOST have?
    – lornix
    Oct 14, 2011 at 23:08
  • 1 gig. When I check free -m it shows that I've got pleanty free and I'm not swapping (the host is headless Deb 6, so it's only running the core system, ssh and virtualbox). Oct 15, 2011 at 19:00

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