Blech.
The newly arrived #Seagate IronWolf drive is toast.
SMART data checks ok, can format as #BTRFS, but the moment I try to write anything to it, all hell breaks loose and the drive basically becomes unresponsive until a reboot (or unplug and re-insert if I had it in the USB enclosure).
Gotta a pickup scheduled with the supplier (#WootWare down in the Cape), hopefully they agree with me and I can get it swapped....