Three traditional file system mount types:
Asynchronous data and meta-data writes (Linux default).
Very fast, but unsafe
Asynchronous data, synchronous meta-data writes (FreeBSD default).
Journaling. Can be very fast, but the code is complicated.
Softupdates is a mechanism for ordering meta-data writes
All the speed of (1), with the safety of (2)
Softupdates and journalling have different results on
different data sets