Journaling vs. Softupdates

[Zev Thompson]

Hi all,

This is addressed in the FAQ to some extent, but that answer seems  
incomplete.

Apparently one of the Google Summer of Code projects is to add journaling  
to UFS. When it already has softupdates, why? I've seen benchmarks that  
seem to indicate that softupdates performs as well or better in most  
cases, though I have nothing on hand to substantiate that. I thought the  
only real disadvantages of softupdates were:

- harder to code and implement (though this is already done, so should not  
be an issue)
- sometimes deleting files does not free space right away

Possibility of data loss, I'm guessing, is the same with either.  
Filesystem corruption is similarly very unlikely.

So why the change? Thanks in advance for any answers.

Zev