@penguin42 yeah it started seeing lots of dmesg errors about it dropping off the bus. It was actually my expansion one that failed (Plextor, 256Gb) . The original 128G intel SSD sees to be going fine. I've rethought my LVM approach and now have a pair of 512gb EVO860's.
@stsquad yep, they do just seem to go when they get upset;
@stsquad I'm curious how it died; did it just disappear, give errors or what? How old was it?