I currently have 3x4TB drives in a RAID-Z1 configuration using FreeNAS, which give me approx. 8TB of usable space in a single volume. I'm approaching 6TB, so I'm considering my options for expansion/migration.
My understanding is that I can't expand the existing ZFS pool/volume.
I'd like to be able to do the following:
Buy an additional 3x 4TB drives and build a Windows Server 2016 Essentials Storage Space with Parity, for a total volume size of approx. 8TB.
Move the 6TB of data from the FreeNAS volume to the Storage Space volume
Move the 3x 4TB physical drives from the FreeNAS server to the Windows server, expanding the Storage Space Parity volume from 3x 4TB drives to 6x 4TB drives, for what I understand would then be a 20TB volume.
Ideally, the final Storage Space Parity Volume would be rebalanced
I'm nervous about single-disk parity with 20TB of data, so I'd happily consider a 7th drive for 2-disk parity.
Is this a viable migration path? Is rebalancing possible?
I'm not committed to moving from FreeNAS to Windows. If there's a better way with hardware controllers or Linux, I'm open to that too.
Note: I had considered buying 3x 8TB drives, for a new parity volume of 16TB, but I figure I can save $500 and end up with a larger single volume by migrating from a 3x 4TB volume to a 6x 4TB volume.