@mcline said in After power outage netgate 4100 won't boot:

[24.11-RELEASE][root@pfSense.home.arpa]/var/log: fsck -fy /
fsck: cannot open `pfSense/ROOT/default': No such file or directory

That looks like it has actually booted completely.

Is it running ZFS or UFS? fsck will only work in UFS installs.

Did you try just reinstalling from USB?

You can fit an NVMe drive to the 4100. It's more difficult than the 4200 but can be done if you have experience with similar devices. The limitation is that the drive must be B+M keyed which is unusual. There are a few threads here with users discussing currently available drives. The 4100, 6100 and 8200 all use the same drives.