From my understanding that you cannot add different size disks to a zfs pool. I already have the pool running how do I use the mismatch drives to form 1 6tb pool do i need to delete the pool and start again or is there a way of converting the pool from zfs to btrfs i am not concerned about the data as it is a cache drive.

You can expand the zfs pool

I have not tried it or know anything about it other than it was released and possible.

37 minutes ago, NathanR said:

You can expand the zfs pool

I have not tried it or know anything about it other than it was released and possible.

Thanks for this I am currently stuck in limbo doing parity check so after that is completed ill take a look

Not sure if ZFS allows mismatched drives to be used if you want the full capacity to be used (i.e. E. TB) but I think not although @JorgeB would be the best for confirming this.

BTRFS does with the ‘Single’ profile although you have no redundancy with the Single profile - but that may be OK for your needs?

57 minutes ago, itimpi said:

Not sure if ZFS allows mismatched drives to be used if you want the full capacity to be used (i.e. E. TB) but I think not although @JorgeB would be the best for confirming this.

BTRFS does with the ‘Single’ profile although you have no redundancy with the Single profile - but that may be OK for your needs?

So it is BTRFS that will allow mismatched drive sizes i am not too interested in redundancy as its just a cache downloading drive just wanted to maximise the space out of 1 pool.

ZFS also can use the full capacity of mismatched drives if you choose a stripe (there's no redundancy).

19 hours ago, JorgeB said:

ZFS also can use the full capacity of mismatched drives if you choose a stripe (there's no redundancy).

Thanks for this i ended up on BTRFS as i missed a little box where the start button for the array was as it was complaining about no file structure something a long the lines of that, didn't notice it until i also saw the same message when trying BTRFS its up and running now.