So I have a bunch of empty space, I'd like to remove more than one empty data disk at once and rebuild parity after new config, this should be fine yeah?

 

The plan: remove two data disks and parity disk, replace parity with one of the remaining empty data disks hit new config and recreate parity.

 

I can't work out a reason for why it wouldn't work so all green?

I don't see anything wrong with your plan, just so long as you make sure you assign the right drive as parity.

 

Sent from a mobile device, sorry for any typos.

 

 

That will work fine -- HOWEVER, do a parity check BEFORE you do this, to confirm all is well.  If there are ANY sync errors, do it again to confirm they were resolved.  [Do correcting checks so any errors are fixed]

 

Once you know you have a "clean" array, then doing a New Config lets you set the configuration however you'd like.

 

This month marks the sad event when I retire my unRAID for tRAID.

I always backup my array config file and print the list of HDD's before making changes (add or remove drives).  I'll generally backup the whole USB stick too since I have to power off the machine to add / remove drives.  It doesn't take very long and it will save a lot of headaches if things go wrong.