I've got a very strange issue none of us have seen, so I'm posting to see if it's unique to our environment or if anyone else has seen it.
-All clients are 10.12.6, hardware is Mini's, Retina's (13 & 15) and current MBP 13" No touchbar, as well as an iMac...so no commonalities so far as hardware...
-Some clients shipped with Sierra, others were upgraded through self-service using the technique for offering Sierra featured on DerFlounder's page (thanks again Rich, you're awesome).
-Affected clients (relatively small number, less than 10% of our fleet) have issues booting - they hang during boot (progress bar gets about 1/3 of the way) although I've had success getting them to boot more reliably with a PRAM reset first. If left alone, some clients will eventually boot after several hours.
-Some clients are hard freezing and need a reboot where things will work okay for 5-15 minutes, then freeze again.
-Here's where it get's weird - the remaining space on the disk you can watch disappear as the client sits idle. It looks like it's being used by the system, but there's nothing there. Honestly it looks like a massive swapfile but I cannot actually locate where it's at. But you can literally look at a finder window with status enabled and watch the free space tick away.
-Re-image and things (so far) are working as expected on a test client.
Has anyone run into something like this? it's very strange and we're all kind of flummoxed since there's been no new policies rolled out except some very basic security remediation, which would have affected at least 125+ more clients if that was the rogue policy causing this strangeness...
Thanks all if anyone is able to offer any insight.

