At some point, `mkfs.ext4` has changed to include `-O metadata_csum` in the default options.  Our kernel builds `crc32c` as a module and at least for people still using `genkernel` while `ramdisk` doesn't support `lvm` rootfs, the module isn't loaded by the initramfs script.  I've fixed this problem where it occurs by building that module into the kernel and using a custom config.  We can fix it for everyone that way; so I propose to test it in harvester.