Notes on resizing partitions to install Linux Mint 20.1

To install Linux Mint I had to go through a few hoops:

• Install Live USB and reinstall grub (see Reinstall Grub on a dual boot when Windows wipes it)
• It turned out I didn’t need to reinstall grub I needed to change the boot order
• It turned out the gparted-like interface which is in the new Linux Mint installer (and allows you to resize partitions before installing) doesn’t show the mount point of partitions, so I had to exit the live USB and run gparted on the Ubuntu partition to double check it was mounted at / then re-open the live USB
  • It turned out that exiting the live USB somehow reordered the boot order, so the live USB would no longer run, so I had to re-enter the BIOS to put the USB drive as primary boot device

Upon re-entering the Linux Mint 20.1 installation wizard ISO from the live USB, to resize partitions and create a new Mint partition, take the option “Something else” (new!) when selecting installation mode (as opposed to “alongside [other OS]” or “remove other OS”

• To make space, click ‘change’ on your other system partition and reduce (e.g. halve) the size
• Click the + on the ‘free space’ that will appear listed below that partition (from the reduction in size) and by default it will take up all of the space you just made available in a new partition.
  • This new partition will be for your new Mint installation but this is not referenced anywhere
  • It will have a tick in the “Format?” column indicating
  • Keep the default “Device for boot loader installation” which will be to the main disk (rather than selecting a partition on that disk), this will mean that the bootloader will have options for all OS partitions [rather than just the Mint one if you were to choose the new Mint partition]
• When you click ‘install now’ it will declare it is about to format the swap partition it detected from your other OS
  • This is not destructive (if you’ve hibernated your other OS somehow er... go switch it off) and the new Mint installation will just share it: this is fine to do