Friday Aug 14, 2009

Growing your Virtual Disks

When I create new Virtual Machines, or guests, in VirtualBox I tend to skimp a little on the size of the virtual hard disk I create because I'm trying to save on host disk space. And this tends to come back and bite me when the guest quickly fills the disk and I run out of disk space in the guest. So you think, "wait a minute, this hard disk is just a file, so why can't I make the file bigger?".

The problem here is that, yes, to the host system it is just a file, but to the guest it is a hard disk and they're not expected to suddenly grow. So if or when they do, you need to tell the guest OS about this, by modifying the partition table too.

So here are a few options that you can use to deal with lack of disk space in the guest:

1. Compact the disk

One option is to not grow the disk at all but reorganize the data on it. Achim told us "How to Compact your Virtual Disks" last month. Note that you don't need to mess around with disk partitions with this option. 

2. Create a new bigger disk 

You could simply create a new bigger disk and copy over the old data  but you still need to tell the guest that the new hard disk has bigger partitions. Here's a step by step guide to doing this.

3. Create a bigger disk to start with but with a smaller root partition

One of the VirtualBox team (thanks Frank!) gave me this tip to creating large virtual disks while controlling host disk space at the same time.

"Instead of creating a dynamically growing disk image with, for instance 20GB, the user should create a large disk image, say, 100GB, but he should only partition the first 20GB by the guest. (ed - you typically get the chance to do this during OS install). Doing so, the disk image will never occupy more than 20GB (plus some maintenance information) as long as the guest doesn't need more. Once the guest is short in disk space, simply increase the guest partition using some common tool, for instance boot the guest with a Ubuntu Jaunty LiveCD and use the Partition Manager to increase the guest partition to your needs (that application can handle NTFS partitions as well). "

4. Using a networked storage server.

If you are using VirtualBox's built-in iSCSI support to a networked storage server such as Sun's Storage 7000 systems, or maybe simply a Solaris server running as an iSCSI target with ZFS, then you can resize the disk easily using:

# zfs set volsize=10G poolname/volname

But you still need to repartition this disk, as you need to do in 2 and 3 above too.

Hope one of these works for you.

- FB 

Wednesday Aug 05, 2009

Sun VirtualBox 3.0.4 released!

The 3.0.4 maintenance release was made available to download from the UsualPlaces earlier today.

The myriad of fixes attempt to squash bugs in areas including SMP, 3D and NAT.

For a fuller list of fixes check out the ChangeLog.

- FB 

Friday Jul 10, 2009

Sun VirtualBox 3.0.2 released!

Just a quick note to say that the 3.0.2 maintenance release is now available to download from the Usual Places.

This release fixes a few problems with the 3.0.0 release including networking hangs, SMP performance and "Solaris-as-a-guest" issues. For a fuller list of fixes check out the ChangeLog.

- FB 

Tuesday Jun 30, 2009

VirtualBox 3.0 is released!

Good news! VirtualBox 3.0 is released. This is the  release where guests went SMP (multiple vCPUs).  And to show what that means here's a screenshot of a MacBook Pro (Intel Core 2 Duo) running:

  • Windows Server 2008 with 4 vCPUs (left hand side);
  • Ubuntu Server with 2 vCPUs (right hand side);

...on a host which has 2 physical CPUs, as can be seen from the Mac's Activity Monitor window bottom of picture. (Click on the image to zoom in).

6 vCPUs from 2

For the interested amongst you, each virtual machine is a separate process on the host. And each process consists of several threads, where some of those host threads represent virtual CPUs, and others represent helper threads that deal with stuff like device access.

Configuring your guest for SMP is a piece of cake. The VirtualBox 3.0 UI has been modified to hopefully be easier to use and we've introduced a simple slider control to determine how many vCPUs you want to assign to your guest.

32 vCPUs

One point to note is that if you assign many more vCPUs than you have physical CPUs the system may run slower because the host spends more time scheduling threads than actually running them. So VirtualBox limits the CPUs you can assign to a guest to twice the number of physical CPUs. i.e. in the example above, 4 vCPUs was the limit of a 2 CPU system in a single guest (you can have several concurrent guests BTW). And on larger server platforms VirtualBox can go to a maximum of 32.

For a full list of what's new see the ChangeLog and download it now from the Usual Places.


Friday Jun 19, 2009

VirtualBox 3.0 Beta Program

If you know what you are doing and you like to live dangerously, you might want to read about the VirtualBox 3.0 Beta which was made available this week.


Tuesday Jun 09, 2009

Sun VirtualBox and Sun VDI Power JavaOne

Even though you may be away from the office attending a conference, the rest of the world moves on and you quite often need to keep up with your day job. At JavaOne this year, Sun provisioned 21,000 Virtual Desktops for the attendees to use to stay on top of things. This blog entry describes briefly how this was done using VirtualBox and Sun VDI...

User's experience

Dotted around the Moscone Center were hundreds of Sun Rays. These were in the Lobby Areas,

Underpass between North and South Halls, 

and Cyber Lounge areas in the Pavilion.

Every JavaOne attendee was given a smartcard as part of their Welcome Kit on registration. And all you needed to do to get your Virtual Desktop was insert this into the nearest free Sun Ray.

The user can then choose which type of Virtual Desktop they want from:

  • Windows 7 
  • Ubuntu 8.10
  • OpenSolaris 2009.06 

Under the hood:

The first time you make this choice your Virtual Desktop virtual machine (vm) is created based on a template in Sun VDI. The virtual machine configuration is held in a MySQL database and the virtual disk image is quickly cloned from the template using a feature of ZFS which underpins the Sun Storage 7000 servers that were in use. Then Sun VDI chooses a VirtualBox server (based on load) and launches the new vm on that server, with the configuration and iSCSI target id that uniquely identifies the new virtual disk.

When you pull your card out the vm suspends after a short period which means resources can be freed up for other users.

When you re-insert your card and launch a previously created Virtual Desktop, the vm is restored from disk (note that this can be to a different VirtualBox server than the original session ) and you are good to go.

Here is my Windows 7 Virtual Desktop.

Administrator Experience 

To manage the 21,000 virtual desktops we had 2 guys (admittedly smart guys).

And the whole thing was powered by a single rack:

The rack consisted of:

  • 4 VDI servers - 4 Sun Fire X4450, each with 4 CPUs and 64 GB memory.
  • 5 VirtualBox servers - 5 Sun Fire X4450 servers, each 4 CPUs, 6 cores per CPU and 64 GB of memory.
  • 3 Storage servers - 3 \* 7210 Unified Storage servers.

This was vastly over-spec'ed as we could see using the Analytics of the storage servers:

Thanks to Christian and Thomas (our architects and admins for the week) and kudos to Dirk's and Achim's teams.

- FB 

Saturday May 30, 2009

Sun VirtualBox 2.2.4 released!

Quick one: Version 2.2.4 was made available for download last night from the Usual Places.

What got fixed is listed here.

- FB 

Thursday May 21, 2009

Virtual Appliances

One of the really cool and really powerful features introduced in version 2.2 is the ability to export and import virtual appliances. A Virtual Appliance consists of:

  • description of one of more virtual machines in an OVF file;
  • a set of one or more virtual disk images.

 With VirtualBox you can now easily create virtual appliances by simply exporting your vm's directly from the VirtualBox GUI or on the command line. 

And of course you can import just as easily as you would expect.

For details of how it works and why you might want to do this here's a 9 minute movie. There are chapter markers for Import and Export sections if you want to skip thru it.


Tuesday May 05, 2009

3D graphics acceleration with VirtualBox

VirtualBox 2.1 introduced 3D acceleration in Windows guests and 2.2 introduced support for Linux and OpenSolaris guests. Here's a short video about how this feature can deliver the Compiz effects in a Linux guest.

Saturday May 02, 2009

Still Buzzin'

Fat Bloke had a little time off lately after the excitement of releasing 2.2. But the Buzz around VirtualBox didn't let up and was fueled even more by events such as the launch new versions of Ubuntu and Mandriva, Microsoft's XP-mode with Windows 7 and, of course, Oracle's move for Sun.

So FB has been working hard to catch up and sift thru all the great stuff that has been published in the last couple of weeks. If you want to keep up with the VirtualBox zeitgeist you might want to follow the VirtualBox Buzz blog.


Tuesday Apr 28, 2009

Sun VirtualBox 2.2.2 released!

There were a few problems in the 2.2[.0] release which we have now rectified in this new maintenance release.

It is available for the usual platforms from the usual places and, BTW, this one works really well with Ubuntu 9.04.

Ubuntu 9.04

Wednesday Apr 08, 2009

Sun VirtualBox 2.2 is released!

It's out there so what does it contain? In a nutshell:

Share and Publish

  • export and import virtual machines using OVF support

Faster and more Powerful

  • hypervisor speedups
  • guests can have a max of 16Gb RAM (up from 3.5Gb)
  • 3D acceleration for OpenSolaris and Linux guests


  • smarter defaults (audio, USB, VT-x)
  • Host-only networking for using server guests offline
  • removed previous limitations such as not mixing VT-x and non-VTx guests. (64- and 32-bit guests)

You can hear all about these features in the April edition of The VirtualBox Live show and I'll be discussing a few of these features in more detail in the coming weeks.


Wednesday Feb 18, 2009

Sun xVM VirtualBox 2.1.4 is released!

Just a quick note to say that there's a maintenance release now available (version 2.1.4) 

- FB 

Thursday Feb 12, 2009

How to configure a 64-bit guest

One of the new features of version 2.0 was the ability to run 64-bit guests. However, this initially required a 64-bit host platform to function. For example, to run Windows Server 2008  as a guest on your Windows or Linux PC, you had to upgrade your host system first. This was clearly a "bad thing".

With version 2.1, the VirtualBox team removed this restriction and you can now run 64-bit guests on your 32-bit host. There are still a couple or pre-requisites...


  • your CPU needs to be 64-bit capable (e.g. Intel Core 2 Duo, AMD Athlon, etc);
  • your CPU needs to be Intel VT-x or AMD-V capable (for AMD systems this may need to be enabled in the BIOS). We call this Hardware Virtualization.


Here's how it is done:

  1. Create a new virtual machine
  2. When specifiying the OS type,  select the family and the 64-bit version in the dropdown list box
Create New Virtual Machine

If you do not see the 64-bit options in the drop-down list then VirtualBox thinks that your machine has not met the pre-requisites above.

Choosing the 64-bit version causes VirtualBox to create a vm which uses the VT-x/AMD-V technology of the CPU, and uses IO APIC too.

That is all there is to it. Continue installing your 64-bit OS into this vm as usual.


There is one limitation which is a bit of a pain...

You can run multiple guests at the same time (as you have always been able to do) and you can run a mix of 64-bit and 32-bit guests simultaneously too.  But you cannot run 2 vm's, one of which uses VT-x disabled and another, VT-x enabled. Else you will see something like this error message:

VirtualBox VM

To get around this you can either simply save the running guest before resuming the other, or configure all your vm's to use VT-x/AMD-V.

Being able to run 64-bit guests means that you can easily kick the tyres of 64-bit OSes such as Microsoft's Windows Server 2008 R2 Beta 1.

That's what I did in this episode of "The Fat Bloke's Shorts"

- FB

Friday Jan 30, 2009

The "VirtualBox Live Show"

The VirtualBox crew are starting up a regular "live" webinar (which will be recorded) where they'll share the latest developments in the VirtualBox world. Here are the details of the first episode....

Register now for a free webinar discussing what's new in VirtualBox, including a live demo and Q&A.

Join Us.

VirtualBox Live Show
Free Webinar discussing what's new in VirtualBox, including a live demo and Q&A.

Dear Fat Bloke,
The world's most popular open source virtualization software just got better. If you need a fast, easy and flexible enterprise-class virtualization solution, you won't want to miss this Webinar. The February 2009 edition of the VirtualBox Live Show will bring you all the latest news from the world of VirtualBox, including everything new in VirtualBox 2.1(.2), a live demo, and Q&A.

WHO: Andy Hall, VirtualBox Product Manager

WHAT: VirtualBox Live Show

WHEN: February 4, 2009, 8:00 am PST / 11:00 am EST
(The presentation will be approximately 45 minutes long followed by Q&A.)

WHERE: Simply access the web seminar from the comfort of your own office.

WHY: Learn the latest tricks to turn your PC into an easy-to-use virtualization platform with Sun xVM VirtualBox, the enterprise-class open source software that runs on all major operating systems and eliminates the need for tradeoffs or multiple hardware systems.

Register here for the free VirtualBox Live Webinar now.
If you have any questions or feedback, please send a message to
Thank you,
Sun Microsystems, Inc.
Sun Microsystems, Inc., 500 Howard St., M/S: USFO07, San Francisco, CA 94105 USA
© 2009 Sun Microsystems, Inc. All rights reserved.

Fat Bloke


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