Guest Additions

Probably the most common need is to install guest additions. Because the virtual machines are running in headless mode, there’s no menu to easily select “Install Guest Additions”. However, this option merely automates the mounting of an ISO. We can replicate this functionality from the command line. Note that the path to the ISO may vary depending on your host environment.

#run this on your host
VBoxManage storageattach "LAMP1" --storagectl "IDEController" --port 1 --device 0 --type dvddrive --medium /usr/share/virtualbox/VBoxGuestAdditions.iso
#run these commands on the guest
#install packages necessary to build and install the additions
sudo apt-get install build-essential linux-headers-`uname -r`
#run the Guest Addtions installation and reboot
sudo mount /media/cdrom
sudo /media/cdrom/VBoxLinuxAdditions-x86.run

If you’d like to mount another disc, you’ll need to eject the ISO first.

#unmount the disc in the guest
sudo umount /media/cdrom
#instruct VirtualBox to emulate an empty drive
VBoxManage storageattach "LAMP1" --storagectl "IDEController" --port 0 --device 0 --type dvddrive --medium emptydrive

Shared Folders (guest additions neccessary for shared folders)

Shared folders are a common way to transfer files between guest and host. First, you’ll need to successfully install guest additions. Once done, adding is easy as following the below template. Just customize the VM name, share name and host path.

VBoxManage sharedfolder add "LAMP1" --name "dropbox" --hostpath ~/Dropbox/

Changing the MAC address

This is probably not a common need, but if you’ve got IP addressed reserved for certain devices, you’ll need to ensure the MAC address stays the same between VM setups and tear-downs. The change from auto-generated is easy.

#First, check the current MAX address
VBoxManage showvminfo "LAMP1"|grep NIC\ 1:
#Now, set the MAC address to whatever you want
VBoxManage modifyvm "LAMP1" --macaddress1 0800279859FF

USB support

I’m not sure how many people use USB support in headless mode, but if you need to mount a device directly in the guest OS, VirtualBox provides that ability. Permission settings borrowed from http://wiki.flexion.org/VirtualBox.html

#Add proper permissions to USB device
printf "none /proc/bus/usb usbfs devgid=%s,devmode=664 0 0" $(grep vboxusers /etc/group | cut -f3 -d':') | sudo tee -a /etc/fstab
VBoxManage modifyvm "LAMP1" --usb on --usbehci on

VM Management with VBoxTool

By far, the best tool I’ve used for automated VM management is VBoxTool. It’s really just a collection of scripts to automate tasks, but the killer feature is the autostart and autosave of virtual machines on boot and shutdown. While it facilitates other aspects of VM management, those two alone make it worth the trouble of configuring it.

mkdir ~/vboxtool
cd ~/vboxtool
wget "http://downloads.sourceforge.net/project/vboxtool/vboxtool/0.4/vboxtool-0.4.zip?use_mirror=kent" -O vboxtool-0.4.zip
unzip vboxtool-0.4.zip
cd script
chmod 755 vboxtool*
sudo chown root:root vboxtool*
sudo mv vboxtool /usr/local/bin
sudo mv vboxtoolinit /etc/init.d
sudo update-rc.d vboxtoolinit defaults 99 10
sudo mkdir -p /etc/vboxtool
cd /etc/vboxtool
#Configure /etc/vboxtool/machines.conf to register machines with VBoxTool
echo 'LAMP1,3391' | sudo tee -a machines.conf
#Configure /etc/vboxtool/vboxtool.conf to indicate which user that machines should start under
printf "vbox_user='%s'" $(whoami) | sudo tee -a vboxtool.conf
vboxtool autostart

If for some reason you ever decide to remove VBoxTool, you’ll need to unregister it from boot with the below command.

update-rc.d -f vboxtoolinit remove

VBoxWeb

Although the VBoxWeb project still has some rough edges and the blog isn’t updated often, it holds a lot of promise. If you’d like to check it out, use the following commands to download and install it. Full guide available on their own website.

sudo apt-get install python-simplejson subversion
svn checkout http://vboxweb.googlecode.com/svn/trunk/ vboxweb-read-only
cd vboxweb-read-only
python VBoxWebSrv.py adduser $(whoami)
#Below starts VBoxWeb in the background
python VBoxWebSrv.py &

The only assumptions I’m making is that a fresh, recent version of Ubuntu is installed on some relatively recent hardware and you have an ISO of the OS installation. Ideally, you’re using an Intel Core 2 Duo or better. I installed it with a normal Desktop Edition, but this guide is targeted at command-line management. You’re welcome to install Server Edition in which you’re getting a command-line only version of Ubuntu to reduce system requirements and operate with utmost efficiency.

Install VirtualBox

1. Add VirtualBox repositories to apt’s sources (this assumes they’re not already there)

   printf "\n# VirtualBox\ndeb http://download.virtualbox.org/virtualbox/debian karmic non-free\n" | sudo tee -a /etc/apt/sources.list

2. Install the public key

   wget -q -O - http://download.virtualbox.org/virtualbox/debian/sun_vbox.asc |  sudo apt-key add -

3. Update repo contents and upgrade

   sudo apt-get update && sudo apt-get upgrade

4. Install main VirtualBox package

   sudo apt-get install virtualbox-3.1

That’s all there is to getting VirtualBox installed. Unfortunately, it’s not too useful without any virtual machines or operating systems, so that will be our next step.

Create a Virtual Machine

1. Create a Virtual Machine named “LAMP1″ and keep it registered

   VBoxManage createvm --name "LAMP1" --register

2. Configure the new VM. The setting should be somewhat obvious, so feel free to tweak as necessary. Memory = 256MB, ACPI, hardware virtualization, and VRDP enabled. Set the VRDP port to 3391. Make NIC1 be of type bridged and bind that bridge to eth0. If you’re using wireless, you might need to change this to wlan0 or something similar.

   VBoxManage modifyvm "LAMP1" \
   --memory 256 \
   --acpi on \
   --hwvirtex on \
   --vrdp on \
   --vrdpport 3391 \
   --nic1 bridged \
   --bridgeadapter1 eth0

3. Create a new hard drive file of size 10GB and remember it.

   VBoxManage createhd --filename LAMP1.vdi --size 10000 --remember

4. Add a SATA storage controller to the VM for the hard disk to attach to.

   VBoxManage storagectl "LAMP1" --name "SATAController" --add sata

5. Now, bind the VDI file to the SATA controller. This is like plugging the hard drive into a SATA port.

   VBoxManage storageattach "LAMP1" --storagectl "SATAController" --port 0 --device 0 --type hdd --medium "LAMP1.vdi"

6. Also add an IDE controller for things like ISO mounting

   VBoxManage storagectl "LAMP1" --name "IDEController" --add ide

7. Attach OS installation media to the IDE controller.

   VBoxManage storageattach "LAMP1" --storagectl "IDEController" --port 0 --device 0 --type dvddrive --medium ~/ubuntu-9.10-server-i386.iso

That’s it, you’re done! Well, mostly. Depending on your exact circumstances, you may have to tweak a few things.

Verify and Start

1. Verify everything looks good

   VBoxManage showvminfo "LAMP1"

2. Start the Virtual Machine.

   VBoxHeadless --startvm "LAMP1"

The major component to managing virtual machines on the command-line is simply knowing the correct commands and parameters to configure everything. I plan to write an addendum which addresses some advanced features such as USB, remote management, and automated startup/shutdown.

Update: The addendum for extra features is up.

According to the VirtualBox Web Console Blog, quite a few of the fixes released are directly related to requests from that project. As noted in my preview, VirtualBox Web Console is a great idea, but is just too immature for use. With this new VirtualBox version, hopefully that problem will fix itself even faster.

Aside from Python API-replated adjustments, there’s nothing too out of the ordinary, but I see a couple things that pique my interest:

• VRDP remote USB protocol 3
  • At first, I thought this had to do with USB 3.0, but it turns out, this is simply an update that “allows to send large packets as fragments” – whatever that means.
• Restricts guest RAM site to 1.5GB with 32-bit Windows hosts
  • A curious inclusion. Why should it be restricted at all? According to a forum moderator, “there is no room in the 32 bits virtual address space to map the whole guest ram”. I don’t understand how this suddenly changed from prior releases.

Here’s the full changelog as detailed on the official website:

• VMM: fixed IO-APIC overhead for 32 bits Windows NT, 2000, XP and 2003 guests (AMD-V only; bug #4392)
• VMM: fixed a Guru meditation under certain circumstances when enabling a disabled device (bug #4510)
• VMM: fixed a Guru meditation when booting certain Arch Linux guests (software virtualization only; bug #2149)
• VMM: fixed hangs with 64 bits Solaris & OpenSolaris guests (bug #2258)
• VMM: fixed decreasing rdtsc values (AMD-V & VT-x only; bug #2869)
• VMM: small Solaris/OpenSolaris performance improvements (VT-x only)
• VMM: cpuid change to correct reported virtual CPU id in Linux
• VMM: NetBSD 5.0.1 CD hangs during boot (VT-x only; bug #3947)
• Solaris hosts: worked around an issue that caused the host to hang (bug #4486)
• Solaris hosts: fixed a rare host system deadlock when using bridged networking
• Solaris hosts: fixed a potential host system deadlock when CPUs were onlined or offlined
• Solaris hosts installer: added missing dependency for UTF-8 package (bug #4899)
• Linux hosts: don’t crash on Linux PAE kernels < 2.6.11 (in particular RHEL/CentOS 4); disable VT-x on Linux kernels < 2.6.13 (bug #1842)
• Linux/Solaris hosts: correctly detect keyboards with fewer keys than usual (bug #4799)
• Mac OS X hosts: prevent password dialogs in 32 bits Snow Leopard
• Python WS: fixed issue with certain enumerations constants having wrong values in Python webservices bindings
• Python API: several threading and platform issues fixed
• Python shell: added exportVM command
• Python shell: various improvements and bugfixes
• Python shell: corrected detection of home directory in remote case
• OVF: fixed XML comment handling that could lead to parser errors
• Main: fixed a rare parsing problem with port numbers of USB device filters in machine settings XML
• Main: restrict guest RAM size to 1.5 GB (32 bits Windows hosts only)
• Main: fixed possible hang during guest reboot (bug #3792)
• GUI: fixed rare crash when removing the last disk from the media manager (bug #4795)
• VBoxManage: fixed guestproperty for Mac OS X hosts (bug #3806)
• VBoxManage: fixed setting guest properties with –flags or -flags
• Webservice: fixed a severe memory leak, at least on platforms using XPCOM
• Serial: fixed host mode (Solaris, Linux and Mac OS X hosts; bug #4672)
• VRDP: Remote USB Protocol version 3
• SATA: fixed hangs and BSODs introduced with 3.0.4 (bugs #4695, #4739, #4710)
• SATA: fixed a bug which prevented Windows 7 from detecting more than one hard disk
• SATA/SCSI: fixed rare random guest crashes and hangs
• SCSI: fixed problem with Fedora 11 refusing to boot after kernel update
• iSCSI: fix logging out when the target has dropped the connection, fix negotiation of simparameters, fix command resend when the connection was dropped, fix processing SCSI status for targets which do not use phase collapse
• BIOS: fixed a bug that caused the OS/2 boot manager to fail (2.1.0 regression, bug #3911)
• PulseAudio: don’t hang during VM termination if the connection to the server was unexpectedly terminated (bug #3100)
• Mouse: fixed weird mouse behaviour with SMP (Solaris) guests (bug #4538)
• HostOnly Network: fixed failure in CreateHostOnlyNetworkInterface() on Linux (no GUID)
• HostOnly Network: fixed wrong DHCP server startup while hostonly interface bringup on Linux
• HostOnly Network: fixed incorrect factory and default MAC address on Solaris
• HostOnly Network: fixed the problem with listing host-only interfaces on Mac OS X when all physical interfaces are down (bugs #4698, #4790)
• DHCP: fixed a bug in the DHCP server where it allocated one IP address less than the configured range
• E1000: fixed receiving of multicast packets
• E1000: fixed up/down link notification after resuming a VM
• NAT: fixed ethernet address corruptions (bug #4839)
• NAT: fixed hangs, dropped packets and retransmission problems (bug #4343)
• Bridged Network: fixed packet queue issue which might cause DRIVER_POWER_STATE_FAILURE BSOD for Windows hosts (bug #4821)
• Windows Additions: fixed a bug in VBoxGINA which prevented selecting the right domain when logging in the first time
• Windows host installer: should now also work on unicode systems (like Korean, bug #3707)
• Windows host installer: check for sufficient disk space
• Shared clipboard: do not send zero-terminated text to X11 guests and hosts (bug #4712)
• Shared clipboard: use a less CPU intensive way of checking for new data on X11 guests and hosts (bug #4092)
• Guest Additions: do not hide the host mouse cursor when restoring a saved state (bug #4700)
• Windows guests: fixed issues with the display of the mouse cursor image (bugs #2603, #2660 and #4817)
• SUSE 11 guests: fixed Guest Additions installation (bug #4506)
• Guest Additions: support Fedora 12 Alpha guests (bugs #4731, #4733 and #4734)

The mission of the VirtualBox Web Console project is very simple: implement the VirtualBox user interface using modern Web 2.0 techniques like AJAX. It will start with very little functionality but our intention is to grow this quickly into a very powerful and easy to use web interface for either a single VirtualBox host or a group of hosts.

The code is certainly its infancy and it seems that those responsible for its development plan on taking advantage of community contributions — as evidenced by being hosted on Google Code. The team has a few blog posts outs, but it’s really too early to tell how responsive they’ll be to the community at large.

Basics

The project exposes itself as a website running on Python and looks largely like the native console, with a listing of VMs on the left and details on the right. The obligatory Start, Pause, and Power buttons are available, as are the settings summary and description. While it looks like a great start, there’s a lot of planned functionality that isn’t completed. Clicking the Settings button reports the message, “Change VM settings not implemented!” There’s even filler menus with filler text.

As expected with such an early release, the web application is broken all-around. Creating a new VM generates a wizard to guide you through the process, but many portions are unlabeled and confusing. This isn’t a knock against the team – any project where I have to checkout from source repository with live changes spells disaster. Simply be forewarned if you are interested in testing the project on your own.

Because of the state of the project, initial setup is more involved in a standard project. Fortunately, the team documented an instruction wiki page that overviews the major requirements. It’s slanted towards Windows, but any seasoned Linux or OS X user should be able to adapt as required.

Moving beyond settings

Aside from standard virtual machine maintenance, the golden nugget of this project appears to be the Console functionality implemented using a component creatively named, “Sun RDP Web Control”. In actuality, this is intended to be an embedded Adobe Flash application which will act as a liaison between the user and the RDP session.

I say intended because I couldn’t get the functionality to work when I post-forwarded the embedded web server. When accessing the website on the same network, it worked flawlessly – every action I performed in the Flash component appeared instantly in the actual virtual machine. After a bit of discussion on the Architecture blog post, it seems that the RDP Web Control mostly acts as a browser-embedded RDC client. That is, it connects to the RDP port of the target machine. If it doesn’t happen to be on your network, you’ll never connect. I hoped the component was a bit more complicated than that, but alas not. A workaround, I suggested was the possibility of overriding the IP and port. This would allow a user to port-forward the RDP locally and force the connection to that local port. While I would appreciate a true interface to pass-through actions, this would be an acceptable compromise.

Furthermore, while the idea is lofty, I think relying on RDP is ultimately a mistake, as this features is only available in the closed-source edition. Those intending to use OSE will be out-of-luck.

Wrap-up

The project holds much promise. If they deliver even a basic utility implementing the most common management features, plus the interactive console, VirtualBox will have a real winner on their hands. As with expanded disk file support and 3D acceleration, Sun has continued making solid jabs at other virtualization vendors. If the feature pace is kept up and the community stays involved, other virtualization products might find themselves leapfrogged in popularity.

The full changelog appears below:

VMM: 64 bits guest stability fixes (AMD-V only; bugs #3923 & #3666)

VMM: SMP stability fixes (AMD-V only)

VMM: SMP performance improvement (esp. for Solaris guests)

VMM: eliminated several bugs which could lead to a host reboot

VMM: fixed OS/2 ACP2 boot floppy hang (VT-x only)

VMM: small performance improvement for OpenSolaris guests (AMD-V only)

VMM: fixed CentOS/Xen reboot (software virtualization only; bug #4509)

SATA: fixed hangs / BSOD during Windows XP installation (bug #4342)

SATA: mark the ports as non hotpluggable (bug #3920)

3D support: fix deadlocks and context/window tracking for multithreaded applications (bug #3922)

3D support: fix memory leaks when terminating OpenGL guest applications

3D support: fix crash in Call of Duty

NAT: using two or more NAT adapters in one VM was broken (3.0.0 regression)

NAT: fixed network communication corruptions (bugs #4499, #4540, #4591, #4604)

NAT: fixed passive ftp access to host server (bug #4427)

iSCSI: fixed cloning to/from iSCSI disks

GUI: fixed path separator handling for the OVF export on Windows (bug #4354)

GUI: the mini toolbar was only shown on the first host display (bug #4654)

GUI: added a VM option to display the mini toolbar on top

GUI: don’t crash when adding plus configuring host-only network interfaces

Shared Folders: fixed selection of a drive root directory as a shared folder host path in VirtualBox (Windows host only)

USB: fixed a bug that may have rendered USB devicefilter settings inactive (3.0.2 regression, bug #4668)

Guest Additions: report the Guest Additions version to the guest properties (bug #3415)

Mac OS X hosts: fix creation of VMDK files giving raw partition access (bug #1461)

Mac OS X hosts: improved support for Snow Leopard

Linux hosts: fixed problems leading to wrong colors or transparency in host windows with some graphics drivers (bug #3095)

Linux hosts: hardware detection fallbacks if the hal service fails to find any DVD drives.

Linux and Solaris hosts: Work around color handling problems in Qt (bug #4353)

Solaris hosts: fixed memory leaks in host-only networking

Solaris Installer: fixed incorrect netmask for Host-only interface (bug #4590)

Solaris Installer: added package dependency for Python and Python-devel (bug #4570)

X11 guests: prevent windows from being skipped in seamless mode KDE guests (bugs #1681 and #3574)

X11 guests: fixed screen corruption in X11 guests when large amounts of video RAM were allocated (bug #4430)

X11 guests: some fixes when switching between host and guest-drawn mouse pointers.

X11 guests: fixed an issue which caused seamless mode to stop working as it should (the main issue listed in bug #2238).

Just as VirtualBox 2.0 added a whole host of amazing new features, so too will VirtualBox spring forward, bringing it closer to feature parity with products like Parallels Desktop and VMWare Fusion. The major whiz-bang feature for VirtualBox 3.0 seems to revolve around improved 3D graphics support. Sun is claiming support for Direct3D 8/9 for Windows guests and OpenGL 2.0 for Window, Linux, and Solaris guests. In addition to these major features, the typical slew of bug fixes and minor enhancements have been added.

Setup

I downloaded and installed the Windows binaries of the new beta on my Vista 32-bit laptop. The specifications of the laptop aren’t great, but I was curious specifically about how well 3D Acceleration worked, even with limited support.

After verifying that 3D Acceleration was enabled in Settings?Display?Video, my first stop is at the Windows Experience Index. In the past, due to the lack of Direct3D support, graphics have been a particularly weak point, forcing Windows to not allow the Aero Glass theme to be used. Unfortunately, using Windows 7 build 7100 64-bit, I was unable to successfully complete the test and received the error message, “The Windows Experience Index for your system could not be computed. Could not measure video playback performance.”

I then realized I should update the VirtualBox Guest Additions (Devices?Install Guest Additions…). The installer that loads has an option to install Direct 3D support, which is deselected by default. During the installation, a nefarious notification message was posted warning the use that Windows File Protection may pop up, since some OS files were replaced. After configuration is complete, Guest Additions request a reboot, which I granted. Unfortunately, none of this changed the error message I received while measuring the WEI.

Checking the Device Manager, I see the Display adapter installed is listed as “VirtualBox Graphics Adapter” with a Hardware ID of “PCI\VEN_80EE&DEV_BEEF&SUBSYS_00000000&REV_00″.

OpenGL

I went about checking 3D performance in other ways, specifically demos. My first stop was QtGears, glxgears for Qt. Even on my paltry hardware, I received approximately 750FPS. Running the same benchmark with 3D Acceleration off returned a speed of about 300FPS. Clearly, the OpenGL is working, as it was initially implemented back in VirtualBox 2.1.0.

Direct3D

I then ran the DirectX Diagnostics tool, dxdiag.exe. It reported that both DirectDraw Acceleration and Direct3D Acceleration were Enabled, but AGP Texture Acceleration was Not Available. Furthermore, in the notes section, it reported “No problems found”. When running 64-bit DxDiag, Direct3D was reported to be Not Available. Predictably, when running with 3D Acceleration off, even the 32-bit DxDiag reported that Direct3D Acceleration was Not Available.

Turning 3D Acceleration back on, I attempted to run Futuremark’s 3DMark ’03. Upon launch, it warned, “Hardware does not support multitexturing with at least 2 textures. 3DMark03 will not run properly.” and “Hardware does not support cube textures. 3DMark03 will not run properly.” and “Hardware does not support compressed textures (DXT1 and DXT3). 3DMark03 will not run properly.” and “Hardware does not support stencil buffer. 3DMark03 will not run properly.” and finally, “Your system cannot run any game test of 3DMark03. Please install and run 3DMark2001 for more comprehensive benchmarking.”

After installing and running 3DMark2001 to test Direct3D 8, I was still unable to tun the demo. I’m not sure what extra steps are necessary, but at least one person had a bit more luck than I.

Miscellaneous

Clearly, some great work has been done to support 3D rendering in virtual machines, but there are a few things missing. I’d love for this support to exist in time for the final release, especially to enable Aero Glass in Win7.

Open Virtualization Format

The open standard virtual application format, OVF, has been integrated into the 2.2 release of VirtualBox. Along with actual format support, friendly import and export graphical utilities have been added. Citrix, Microsoft, and VMWare have pledged support for the format. Essentially, OVF is a packaged format of both the physical disk files and configuration values. Ideally, this will be a platform-agnostic way to introduce virtual applications to the masses.

Host-only networking

VirtualBox again introduces improved networking options in a major revision. In previous versions, bridged networking was highly improved. VirtualBox 2.2.0 brings us “host-only” networking. This new networking mode is an amalgamation of features from bridged and internal. Like bridged networking, the VMs can communication with each other and the host as if they were physically connected. But as with host-only networking, the physical host interface need not exist – instead they can communicate as if they were set to internal networking (that is, without connection to the physical network).

Host-only Settings

Using host-only networking requires that a software network interface is created on the host and thus is prone to being able to intercept commands with a packet sniffer. However, this may be a desired side effect, especially when using software appliances to learn about networking. To enable communication with the physical network the host is attached to, a second network interface of type bridged must be setup.

To me, it seems like internal plus host networking could have easily accomplished this. I honestly don’t understand the particular need for this feature aside from better supporting the initiatives of OVF.

3D Support

Continuing the trend of hardware-accelerated Open3D in guests, the VirtualBox team has added support for Linux and Solaris. These OSs now join Windows in this prestige. Additionally, I noted an exciting proposition in the user manual at the very end of page 70, “Direct3D is not yet supported and will be added in a future release“. Obviously, because this is a Windows technology, support would only exist on Windows guests, but the very thought of this is promising.

Miscellaneous

In addition to the major points above, there are a slew of smaller changes and bug fixes. A few highlights include:

• Hypervisor optimizations
• Increased memory limits on 64-bit hosts to 16GB
• Hardware virtualization support is enabled by default
• Addition of C API (joining C++, Java, Python and Web Services)
• Support additional VMDK file variants
• Audio adapter is enabled in GUI by default

Problems

VirtualBox 2.2.0 is another high-quality release from Sun, however this revision has a small hiccup in the installer for detecting physical interfaces. This is immediately exposed to the user in the form of a warning in the Machine settings dialog.

Invalid Settings Detected

As you attempt to configure the virtual interface to resolve the problem, it becomes immediately apparent that VirtualBox is unable to see any physical network interfaces. Instead the only option listed is, “Not selected”.

Bridged Network DetailsHost-only Settings

Fortunately, there is an easy workaround. To resolve this issue, simply re-run the installer and select “Repair”. After the process has completed, VirtualBox should see all the host interfaces, and pick up the existing settings.

• Windows 7 is an operating system type in the GUI
  

  Windows 7 OS Type

• Windows 7 is now a supported OS (see Installing Windows 7 Beta 1 in VirtualBox 2.1.0 and Windows 7 in VirtualBox: Shared Folders workaround)
  • The installer now works as expected
  • I still can’t get Shared Folders to work
• Support for 1,023 guests on 64-bit hosts (increased from  127)
• Fixes for certain types of VHD images, including pre-built testing images from Microsoft
• Experimental support for X.org Server 1.6
• Various Mac host polish
• Improved USB support for Linux hosts

The full Changelog is available on the VirtualBox website.

As long as the above requirement is met, you may share the folder you want to access. I say “may” only because if your host OS is Windows, you can access the hidden drive shares directly. If this is the case, skip the next section and head right for the next paragraph. If you’re new to sharing a folder, here are the steps to accomplish it.

Windows

1. Right-click the folder name and choose, “Share…”
   

   Vista Share Menu

2. Verify the user with access is correct. It should be your current account and have Owner privileges
3. Click Share
   

   Vista File Sharing

Ubuntu

1. Browse to a folder using Nautilus (your default file manager when using Gnome)
2. Right-click and choose “Sharing Options”
   

   Ubuntu Sharing Options Menu

3. If this is your first time enabling sharing, you will be prompted to install the service. Authenticate and let the package manager download and configure Samba. I was prompted to reboot my computer, however, I did not reboot and was still able to continue configuring the shared folder
   

   Install Samba service

   

   Ubuntu Nautilus Permissions

Mac

1. Sorry, I don’t have a Mac. If anyone wants to buy me one, or just generate some revenue through ad clicks, I would appreciate it!

You should then be able to access the share by browsing “\\localhost\sharename”. If you opted to skip creating a share, and want to use the built-in hidden shares, specify “C$” as the share name. Authenticate if necessary and you should be browsing your shared folder locally.

1. Once that is complete, switch over to your VM installation (Windows 7 or otherwise)
2. Bring up Computer (Start Orb→Computer)
3. Click the “map network drive” button
   

   Windows 7 Map Network Drive

4. The “Map Network Drive” dialog box will open and you should configure several items:
   1. Drive: Specify your preferred drive letter. I chose “S:”, but any available letter will work fine.
   2. Folder: This should be defined as “\\HostComputer\ShareName”. Alternatively, you can specify the IP address instead of hostname. Because you are now on the guest OS, this should not be “localhost” as above.
   3. Connect using different credentials: I like to check this, just to ensure I can specify the correct login and password instead of using my current user.
   4. Press the Finish button
      

      Windows 7 Map Drive Options

A new window should open with your new share. You can also minimize this window – exposing the underlying Computer window. A new drive letter under Network Location should be available.

That’s it, you’re done. Windows shares don’t always behave as easily as they should, so if you encounter an error, don’t give up. Keep trying and post the error in the comments.

1. If you’ve not yet installed the OS, my first recommendation is to set OS Type to Windows Vista. Although this is largely for display purposes, of all the choices, Windows 7 is the closest in compatibility to Windows Vista.
   

   Select OS Type

2. Go ahead and install Windows just as you would any other: Mount the ISO in the virtual CD/DVD drive and install.
   

   Install Guest Additions

3. Once the VM is finished installing, install VirtualBox Guest Additions. This process might take a few minutes to download, but with enough patience, the ISO will download and mount.
   The problem is, Sun is performing version checking and Windows 7 isn’t yet officially supported. Therefore, when you try to install Guest Additions, you’ll receive the error, “Platform is not supported for Guest Additions yet!”. Here’s the big tip: You must install Guest Additions in compatibility mode.
   

   Guest Additions Error Message

4. To work around this, once the Guest Additions applications pops up, hit Cancel.
   

   Guest Additions Setup Wizard

5. Navigate to Computer (Start Orb?Computer)
   

   Link to Computer

6. Right-click CD Drive (D:) VirtualBox Guest Additions and choose Open.
   

   Explore the Guest Additions CD

7. The “big tip” part:
   1. Right-click VBoxWindowsAdditions-x86 and select Properties.
      

      Guest Addition Properties

   2. When the dialog box opens, switch to the Compatibility tab
   3. Check the box labeled, “Run this program in compatibility mode for”
   4. Select Windows Vista.
      

      Compatibility Settings

8. Hit OK and Run VBoxWindowsAdditions-x86 as normal. The Guest Additions should now install without error and you will be prompted to reboot Windows.
9. After the reboot is complete, you can confirm the installation by verifying that mouse integration works.

Update: Currently, shared folders don’t work, but I’ve posted a workaround.

Best of luck!