Hot spare kicked in! Though I did kinda force it to by yanking a drive and then offline-ing it.. I’ll make the potentially bad drive the new spare, and order a new 2TB. Stuck labels on the ‘old spare’ (scsi-22f6baa1200d00000) as well as the ‘new spare’ (scsi-22f4b4ac400d00000).
Update: ..and thats what I did! Also considering ditching the SSD cache device so that I can stick another spare in that slot. Easy way to keep everything together, and it’ll already be in the server when I need it.. Plus, that frees up the SSD for other more interesting uses.