Due to Dropbox's idiotic decision to limit file system support drastically for no reason other than to piss people off, I have a small ext4 volume hosted on my ZFS pool.
Originally I made it a bit small (only 8 GB) and got Dropbox complaining. Had I created it as partition, enlarging it would be annoying task at best. However, having it exposed as ZFS block volume, resize was trivial.
First I simply increased volsize property and then told ext4 to simply use that additional space (resize2fs command):
Terminalsudo zfs set volsize=16G rpool/data/dropbox
sudo resize2fs /dev/zvol/rpool/data/dropbox
resize2fs 1.44.4 (18-Aug-2018)
Filesystem at /dev/zvol/rpool/data/dropbox is mounted on /home/user/Dropbox; on-line resizing required
old_desc_blocks = 1, new_desc_blocks = 2
The filesystem on /dev/zvol/rpool/data/dropbox is now 4194304 (4k) blocks long.
Doesn't get much easier.