[NTLUG:Discuss] Time to switch away from ReiserFS?

[Chris Cox]

Leroy Tennison wrote:
...
> Chris,
> 
> Thanks for the reply.  As a follow on, what are the pros and cons of
> data journaling?  That's more or less where I was going with this
> question but didn't make that clear.

There's always a performance hit for journaling.  Without it
you have to do a filesystem check to bring a filesystem back to
an integral state after coming down hard (e.g. power hit, kernel
crash).

Full data journaling helps prevent data loss when transactions
are played back on a journaled filesystem when it's being
recovered.  Obviously full data journaling can be the highest
impact on performance... but useful when the data is
VERY important.  If all you do is metadata journaling the
filesystem structure is brought back to an integral state
with some data loss.  There's ALWAYS the potential
for data loss when a system comes down HARD.  Full data
journaling just mitigates it.

Note: Places that have VERY important data are probably
more concerned why the machine went down hard.... an
event that probably should NEVER happen at those shops.

In fact, a lot of people recommend running ext3 (for example)
with data=writeback, just to get performance gains from
the filesystem.... writeback takes things back to just
metadata journaling.  So I guess it all depends on your
infrastructure.

I know our machines simply do not go down (unless we
force it).