How to extend the Ubuntu guest OS’s hard disk for VirtualBox on Mac

Steps:

• resize the VDI file on Mac OS: How to Resize a VirtualBox VDI or VHD File on Mac OS X

• boot the Ubuntu with the image(ISO) and Gparted(resize the partition).

  Note: firstly resize the extension partition (/dev/sda2), then resize the partition (/dev/sda5)

  Ubuntu VM in VirtualBox: How to increase the size of a disk and make small(er) exports for distribution

• reboot the ubuntu with local vdi file and check the result.

references:

How to Resize a VirtualBox VDI or VHD File on Mac OS X

Ubuntu VM in VirtualBox: How to increase the size of a disk and make small(er) exports for distribution

How to Partition, Format, and Mount a Disk on Ubuntu 20.04 Using Command Line