Unfortunately there doesn't appear to be a solution to the size issue in Nemo (or
df
in Terminal). I tried to mount under
/media
instead, because I read automounting works then. It did, but it also automounted all the datasets, which isn't something I want because it clutters up things when you have a few. Tried to set mountpoint to "none" for a dataset. That removed it from the "Devices" list in Nemo, but also removed it from the pool itself there, so I couldn't actually access it.
Therefore I landed on putting them all under
/mnt
and manually mounting via custom settings in "Disks". Have received and set up the 2x 6TB disks with a ZFS file system, and copied over some data, and now also run a "scrub". Everything seems to be working well. Apart from the size issue in Nemo. WIll just have to live with that, until they possibly fix it in Nemo itself. I saw some issues about it on github, but with no traction at all, so that won't happen anytime soon.
Looks like a very solid system though, and since I've set it up mirrored, it's easy to expand. Attach two more disks down the road, and capacity expands. Less storage efficient than a RAIDZ setup, but mirror is faster and actually possible to expand. If others should be interested in trying out this, here is an excellent article about it:
https://arstechnica.com/information-tec ... rformance/
Sadly I got zero compression from the GOG library of games I moved over and updated with downloads, but hopefully the LZ4 compression will help with some other filetypes. In any case, it's pretty cool to have compression on the file system level itself.