I use parted and resize2fs.
both included in libreelec and accessible via ssh.
Call parted and then use the following commands:
select (to select your disk /dev/sda ?)
print (show the size of the disks and partitions)
resizepart (to resize the partition to the new size)
quit
Then call resize2fs following the partition path (probably /dev/sda2, but you should validate-it yourself )
resize2fs /dev/sda2
reboot
Warning: You must be very careful using these tools, as you mich loose everything in your disk.
Post back your results
When I tried rebooting with an SD card running full blown Raspbian, I tried using the gparted command. That failed, because it said the partition was too big for the "msdos" partition table. It appears that I need to convert to the "gpt" type partition table? Is that right? How do I do that and not lose the content of the drive?
Hello!
If you want to use g(ui)parted you have to Install it first.
Raspian command Line:
sudo apt-get update
sudo apt-get upgrade
sudo apt-get install gparted
Sudo startx (gparted needs root)
Then Run gparted
Regards
Nicolas
All you need(ed) to do is/was boot the LE image before trying to copy media to the drive. If the 32k partition contains /storage/.please_resize_me boot scripts detect it, remove the 32k partition, and a new one created at 100% size.
I know this is not a solution to your question, but I don't really understand why you don't use a small usb for booting, & the 8TB usb separately for storage.
What happens, if you get it all up & running the way you asked, & you need to upgrade, do you have to start again repartitioning?
All you need(ed) to do is/was boot the LE image before trying to copy media to the drive. If the 32k partition contains /storage/.please_resize_me boot scripts detect it, remove the 32k partition, and a new one created at 100% size.
I never copied media to the drive. The drive did resize, but only to the max size supported by the "msdos" partition table type. I think it needs to format the drive using the "gpt" table type instead, so it can support larger partition types.
Parted is a great tool, but some are a little scared of the command line.
An alternative would be to grab a linux ISO and put it on a USB stick, boot it and use Gparted to do it graphically.
It is a great and easy to use tool (and yes, resizing and moving partitions always carries risk)
That is true when running on a PC.
But having libreelec running in a RPi4 (as the case), and accessing it by ssh, parted and resizefs are already installed. No downloads, no installs, no other boots.
Or follow chewitt proposal above, for an even easier approach.
I never copied media to the drive. The drive did resize, but only to the max size supported by the "msdos" partition table type. I think it needs to format the drive using the "gpt" table type instead, so it can support larger partition types.
That sounds like it could be a problem limiting your partition size, but DOS partition tables support up to 2TB drives, so it doesn't explain why it would only be 33.6MB. Something else is going on here.
I'm sure you could partition a drive using GUID and manually copy the partitions into it, but then you'd likely need to reconfigure GRUB which would be a pain.
I know this is not a solution to your question, but I don't really understand why you don't use a small usb for booting, & the 8TB usb separately for storage.
What happens, if you get it all up & running the way you asked, & you need to upgrade, do you have to start again repartitioning?
I second this. This is a much better approach. Much simpler, and long term resilient.
Or better yet, rather than local storage, use a NAS and mount network drives 
