Add more storage space to guest OS on VirtualBox 6

Guest OS: Linux Ubuntu 20.04

I am more comfortable adding a new .vdi disk image using the virtual box and then mount that to the existing Linux guest OS. I read somewhere on a Linux/VM forum that changing the storage size of the current disk where you have data available can cause issues. I increased my disk space by adding a new vdi disk.

Here is the article I followed. It is very easy to follow.
https://www.zachpfeffer.com/single-post/add-a-disk-to-an-ubuntu-virtualbox-vm

In my case I didn't install gksu. Instead, I used sudo in place of gksudo. In the article, author is using vmkd as hard disk file type. I used vdi as hard disk file type. Apart from that, all steps are same

Brief outline of the steps:

Create a disk file

1. Right click on the VM you want to add a disk to
2. Click Settings in the context menu
3. Click Storage in the left sidebar
4. Click Controller: SATA and click on the + icon
5. Click Create new disk in the pop up menu
6. Select disk type in the dialog (I chose VDI)
7. Click on Dynamically allocated in the size dialog and click Next
8. Name the disk, select a size and click Next
9. Click OK
10. Note which SATA port the disk is on (for example "Sata port 2")
11. Click Start to start the VM

Partition in Ubuntu

1. In Ubuntu, open a terminal and identify the disk from the output of

   dmesg | grep sd
   

   You will see a disk that matches the size of the one you created. For example it may be /dev/sdc

2. Install gparted (run sudo apt install gparted) and run sudo gparted`

3. Click the device (/dev/sda) in the top corner and switch to the disk you identified (for example /dev/sdc

4. Click Device and then Create Partition Table

5. Leave as msdos and click Apply

6. Click the create new partition icon (top left)

7. Leave everything as is and click Add

8. Click the green check mark to apply all operations

9. Click Apply in the popup and Close* when successfully completed

Mounting the disk

1. Create a mount point (hdd2 is just an example name - change if you prefer something else)

   sudo mkdir /hdd2
   

2. Add a line to /etc/fstab to mount the new partition on boot

   sudoedit /etc/fstab
   

   Add this line

   /dev/sdc1    /hdd2    ext4    defaults    0    0
   

3. Save, exit and restart the VM.

Hope it helps. :)

I'll recommend to run this command again

vboxmanage modifyhd --resize 46080 box-disk002.vdi

and then resize file-system by booting VM from some LiveCD with gparted.

References:

https://www.virtualbox.org/manual/UserManual.html#vboxmanage-modifyvdi