soft updates [was: Better than POSIX?]

Soft updates does not understand hardware write-back caches, NetBSD's journaling does. Given than nearly all commodity systems have write back caches at some level in the I/O path nowadays, and need them for good performance, this is important.

Soft updates was quite complicated code with integration issues, making it very difficult to fix some of the bugs with it. This was mainly down to its structure, which was suited to commercialization (soft updates was initially a commercial offering). It was not necessarily tailored to the BSD systems.

Additionally, journaling gives some nice benefits like no fsck, and fully atomic rename. No fsck is important to NetBSD for the embedded role, and elsewhere is a much bigger story than it was when soft updates came about due to the explosion in storage volume size.