VirtualBox - Expand Disk Image

Navigate to the folder containing your .vdi disk image file.

Run the following command to expand it:

VBoxManage modifyhd disk1.vdi --resize $SIZE_IN_MB

Then boot up the guest and open a terminal.

Enter the interactive fdisk tool for our disk.

sudo fdisk /dev/sda

Print out the partition table if you like. This can be useful.

p

Now we are going to delete all the existing partitions before recreating the root one (don't worry this works).

For each partition, delete it by pressing:

d

... and then entering the partition number. Repeat until all partitions are gone.

1

Create the root partition with:

n

Make it a primary partion

p

Accept the defaults if you wish for the root partition to fill the entire disk. If you get asked whether you wish to delete a signature, I did when testing and it still worked.

Make the partition bootable:

a

Write changes and quit:

w

If you feel you made a mistake and want to quit out without saving changes, use q.

Tell the system to perform a filesystem check next boot:

sudo touch /forcefsck

If you deleted a swap partition (or any other partitions that auto mount), make sure to remove them from /etc/fstab.

sudo vim /etc/fstab

If you accidentally forget this step, don't panic, you will just have to wait a loooong time for the VM to boot up.

Now reboot for the changes to take effect.

sudo reboot

Don't panic if it takes a little longer for your guest to boot up than normal.

Once your guest has rebooted and you have logged in again, resize the filesystem to fill the partition:

sudo resize2fs /dev/sda1

References

• Ask Ubuntu - How do I increase the hard disk size of the virtual machine?
• Programster's Blog - Expand Qcow2 Root Filesystem