My main Proxmox hard drive was filling up recently...
but I realized the partition was only half the size of the disk! (Proxmox was originally installed on a smaller disk and copied to it's current disk with dd.)
So I pulled up the drive partitions:
Partition I wanted to expand
[For spoiler on the one line resize scroll to the end.]
I started to go through the fdisk flow of resizing the partition but paniced once I realized I had to delete the partition, re-write it, and then saw messages like
Created a new partition 3 of type 'Linux Filesystem' and of size 884.4 GiB. and
Partition #3 contains a zfs_member signature. I wasn't sure if the partiton was right or not!
I quickly quit out of fdisk without rewriting the partition. I had remembered something easier from Ubuntu and finally found it! resizepart!
Simple 1 line partition resize to 100%:
I simply ran
parted /dev/sdh resizepart 3 100% and the partition grew to 100% like magic! (Obviously use your appropriate disk letter/partition number.)
I made sure the pool would expand
And confirmed it did by rerunning zpool list!
Note: the proxmox gui didn't recognize the resize until reboot, but as long as zpool did I was confident things were good!