Even as root, ls and find produced too many errors ("Permission denied", "Not a directory", "directory causes a cycle", "Input/output error", etc) when attempting to list all files on disk. Tree worked a treat:
$ tree -a -i -f / > filesystemlist.txt -a All files are listed. -i Don't print indentation lines. -f Print the full path prefix for each file.See also Tree for Windows and LINUX Recursively list all files in a directory including files in symlink directories.
/nix | Feb 06, 2017