I've had Postgresql data on an encrypted external USB drive (encrypted via the OpenBSD FAQ instructions) for about a year and it's worked great.
Recently, I started gettting dmesg messages saying softraid i/o error and it listed various crypto blocks: Feb 18 09:04:14 freda /bsd: softraid0: chunk sd4a already in use Feb 18 09:04:22 freda /bsd: softraid0: sd5: i/o error 0 @ CRYPTO block 27xxx Feb 18 09:04:22 freda /bsd: softraid0: sd5: i/o error 0 @ CRYPTO block 6xx Feb 18 09:04:31 freda /bsd: softraid0: sd5: i/o error 0 @ CRYPTO block 1624932xxx Feb 18 09:04:31 freda /bsd: softraid0: sd5: i/o error 0 @ CRYPTO block 1624811xxx In this case, it happened when I tried to mount a second external encrypted drive. (I don't recall if this is what always triggers the problem.) My drive with Postgresql running was sd5i. I always mount the drives with the DUID after running bioctl. The sd4a above refers to RAID on the second encrypted drive I had plugged in and just run /sbin/bioctl -c C -l softraid0 DUIDHERE.a on. I'm running OpenBSD 6.6-current (GENERIC.MP) #648: Sun Feb 16 13:54:33 MST 2020 dera...@amd64.openbsd.org:/usr/src/sys/arch/amd64/compile/GENERIC.MP Currently, I have Postgresql 12.1p1 but it happened when the previous external drive had 11.6 data also. At this point of course I can no longer access my data. If I reboot then / also fails to unmount. Rebooting is successful though after filesystem checks. Next time it happens I will take a picture of the messages. I thought my external drive was bad so I switched to a new one, but the same thing happened today. So I am just wondering if anyone else has recently started experiencing this sort of problem. I haven't lost any data since I backup early and often, and in any case, fsck has fixed things so far.