Virtualbox: expanding the size of a virtual disk

NoOp glgxg at
Wed May 14 22:34:19 UTC 2008

On 05/14/2008 02:01 PM, Steven Davies-Morris wrote:
> NoOp wrote:
>> On 05/13/2008 06:23 PM, Steven Davies-Morris wrote:
>>> I've been reading through the documentation but can't seem to find
>>> anything in there that lets me tell it grow a VDI from 8gb to 16gb to
>>> 24gb etc. Can I do such a thing? I don't want to create additional disks
>>> or provide access to one of my raw disks just yet (that will come
>>> later). I'm running the current VB 1.60 i386 32 bit version on Ubuntu 8.04.
>> If you find the answer, please post back and advise. I've been trying to
>> figure out a way to do the same, but all I come up with is to create a
>> new VM then run a disk copy program to copy to the other VM.
>> Some suggestions here:
>> <>
> Damn windows!  doesn't take much to fill up that 8gbs!  So I'm going to 
> create a bigger virtual (I think 20gbs will hold all the Windows stuff I 
> need plus data) and copy everything over.  It's all trial and error 
> right now, learning as I go, so I can't be too upset about it.

You might want to hold of for awhile. I have a "disposable" Win2KPro
that I've been playing with that I initially set for 4GB expandable. It
was getting full, so I am just now trying the methods on page two of
that link:


PostPosted: Fri Feb 15, 2008 10:15 am    Post subject: Another
solution 	Reply with quote
1. create a new VDI image with the size you want
2. attach your new image as the slave
3. boot some linux live CD in your virtual machine
4. check /proc/paritions which drive is original and which is new (watch
the size Smile)
5. dd if=/dev/olddrive of=/dev/newdrive (in the most cases dd
if=/dev/hda of=/dev/hdb)
6. reboot
7. attach your new image as the primary master
8. boot the OS and use some software for resizing partitions (e.g.
parted in linux or partition magic in windows - if you use linux you
can't use parted on master partition, so you can use your live linux cd
9. well done - tested on Windows XP guest and FC6 host and it works

PostPosted: Mon Feb 25, 2008 3:28 am    Post subject: 	Reply with quote

I like your method and it worked great for me. I did the following to go
from 6GB to 10GB

1. Booted up using the SYSRECCD from
2. I executed 'fdisk -l' to see both the partitioned 6GB drive (hda) and
the unpartitioned 10GB drive (hdb)
3. I executed 'dd if=/dev/hda of=/dev/hdb'. Both vdi files were about 5.4GB
4. I executed 'fdisk -l' which now showed hdb as a partitioned drive - cool
5. I started gparted and both partitions looked good. I could have
resized it then but decided to test it first by making the 10GB drive
the primary and dropping the 6GB drive then starting windows -
everything was good
6. Booted up to SYSRESCD again and this time used gparted to resize the
first parttion to use the full 10GB disk - size on disk unchanged at 5.4GB
7. Booted up to windows again and as expected it ran a disk check and
everything was perfect - windows sees 10GB and the vdi will grow as needed

Given that there isn't anything really of value on it that I can't
easily restore, I'm trying the above to move it to a 6GB. You might want
to wait awhile and see if/how I screw up mine first before messing with
yours :-)

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