VirtualBox - all virtual hard disk (vdi) already full...though 2 never used?

Question

I have already browsed quite a bit to find a solution - but ran into several problems.

I have three VM (Windows Host).

• Ubuntu 16, 32bit, I don't use it at all
• Ubuntu 16, 64bit. (Installed: MongoDB, Node, NPM, Vim, Git)
• Nothing yet, it should be for Ubuntu Server later.

When I run my VM Ubuntu-64 a message appears saying there's only 300 mb left one the hard disk, which is strange given that the previous message gave even less.

I tried to go into the vdi file (on windows) to edit it don't know how (tried Notepad - sorry if it's a silly attempt - but it says too large to be opened).

But on top of all that I don't understand how all three virtual hard disks can show "virtual size 8GB" and "actual size 8GB" when I haven't used all three of them at all - or not that much? (The VM I've used these past few days is maybe...three days old!!)

I'm really scared of trying anything just based on what I find - I'd really like not to have to go through the whole installation of my programs again.

Can anyone help me? I really apologize for the newbie question - but I'd really like to continue using that VM (the 64bit), I'm having the time of my life learning Linux commands and all.

UPDATE - removed Ubuntu 32 and Server VMs

This is the output of df -h

~$ df -h
Filesystem      Size  Used Avail Use% Mounted on
udev            630M     0  630M   0% /dev
tmpfs           130M  4,4M  126M   4% /run
/dev/sda1       6,5G  5,7G  460M  93% /
tmpfs           649M  236K  648M   1% /dev/shm
tmpfs           5,0M  4,0K  5,0M   1% /run/lock
tmpfs           649M     0  649M   0% /sys/fs/cgroup
sharedbox       373G   83G  290G  23% /media/sf_sharedbox
tmpfs           130M   52K  130M   1% /run/user/1000

[UPDATE] Follow the steps given by @heynnema below !

Answer 1

The default size for dynamic disks created in Virtualbox is 8GB. This is usually not enough for most guest operating systems to thrive. Sometimes you need to increase the dynamic disk size, after initial creation, and we use the vboxmanage command.

In Windows, to see the vboxmanage commands, in an administrative command prompt window, type:

"C:\Program Files\Oracle\VirtualBox\VBoxManage.exe" /?

To change dynamic disk sizes, we do, like so:

cd path_to_where_your_vdi_is_located

then

"C:\Program Files\Oracle\VirtualBox\VBoxManage.exe" modifymedium disk your_vdi_name.vdi --resize megabytes
or
"C:\Program Files\Oracle\VirtualBox\VBoxManage.exe" modifymedium disk your_vdi_name.vdi --resizebyte bytes

• Change your_vdi_name.vdi to the filename of your dynamic disk.

• Change megabytes or bytes to the final desired size.

• note: modifyhd was used in older versions of vboxmanage.

Once the .vdi dynamic disk has been enlarged, you need to actually increase the Ubuntu partition size to fully use the extra space. Boot the VM to a Ubuntu Live .iso image (by mounting it in the "CD" drive), select Try Ubuntu, and use gparted to set the swap partition to swapoff and then to move the swap partition to the right (if it's to the right side of the Ubuntu partition), and resize the Ubuntu partition on /dev/sda1 to its maximum size. (note: if the Ubuntu and swap partitions reside in an extended partition, you'll have to resize that first).