@SteveITS I have had ZFS since it was available for that reason, and I always reformat the SSD so pfsense install does ZFS from scratch. Yes, I have a very large UPS for many years, small car battery size. The problem is it lasts for a couple of hours since it handles the modem, router, HP 24 port switch, Mac Mini phone system, etc., whereas our power failures average 3 to 8 hours. Sometimes multiple days, one time almost a week! 2.6 always recovered until the modem change, strange but true. Trying to login to pfsense 2.6 only returned the dreaded "502 Bad Gateway Nginx error". Had to power off/on. Waiting to see what happens to 2.7.2. I'm thinking possible ethernet driver issue with a different chip in the S34 than the S33, which may be fixed in 2.7.2. The next power failure will be the test.
My plan is after Pfsense 2.8 is released I will buy a new box for it with 2.5G ethernet to the modem which hopefully will be fine.
Thanks for the comments.