Some Background
So I have a XEN-HVM and a KVM server. Six+ months ago the XEN server was having IO issues (raid resync) so I disabled journaling on the Ext4 filesystem. I saw a huge improvement in IO write speed and significantly less IOwait time. Since then IO speed is back to normal and I'm happy.
Recent Situation
This last week I purchased a KVM container from a provider here and saw a generally high amount of IOwait from the journaling process with a max write speed of around 50-60M/s (killing mysql). Just for kicks I disabled journaling again and saw a relative huge improvement on writes (100-110M/s), almost double in write speed improvements.
I almost feel that I shouldn't need to disable journaling to make a container work, but I'm not complaining.
The Muse
I understand why journaling is needed (saved me a couple of times), but it almost seems like a larger benefit to disable it (since we have raid, hopefully).
Any opinions or comments on journaling?