If my root filesystem is btrfs on an SSD, will my Windows 7 Virtual Machine guest run better if I install it to a raw partition than if I install it to a file on the btrfs partition?

Host OS: Ubuntu 11.10 (Oneiric) amd64 desktop

  • Interesting question - if you install W7 on a physical hard disk, it may eat your bootloader. I know you're asking about speed, so you could use a tmpfs to get the full speed of RAM.
    – new123456
    Nov 4, 2011 at 11:24
  • I would install Win7 to a raw partition using the VirtualBox "passthru" virtualisation which prevents the guest from seeing partitions other than the one configured in VirtualBox, so Win7 won't be able to eat the bootloader.
    – Graham
    Nov 7, 2011 at 9:24
  • I see VirtualBox since 4.1 has an SSD option to present the virtualised disk to the guest as an SSD, so Win7 guest would at least know to use SSD optimisation.
    – Graham
    Nov 7, 2011 at 9:40

1 Answer 1


I believe that it will be faster to run the VM from a raw partition after the SSD's blocks have all been written to, because TRIM commands from the guest OS will be passed through to the SSD, which would not be the case (AFAIK) if the VM were running from a file.

I've since written a blog post describing how to set up a Windows 7 guest running from a raw SSD partition under an Ubuntu 11.10 host.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.