First time forum-poster here :). I recently migrated from FreeNAS to OMV and while it's had it's challenges I think I'm largely there. I've created a RAID Mirror with 2 x 4TB disks and it's populated with data. I would now like to expand this mirror by adding another 2 x 3TB disks, however I now get the above error "/dev/sda not large enough to join array" when I use the "Grow" button in the Storage->Raid Management menu option. I can't imagine I need another set of 2 drive identical to the existing ones in the mirror.
Has anyone perhaps come across this before and able to advise on how to resolve?
Thanks very much