Comment 70 for bug 574910

I didn't mean to imply that the occasional unresponsiveness was fixed by using the new test kernel, it was more of a hope. That hope was dashed a few days ago, while I was not around we experienced another spike that lasted for 1h 10 minutes during which the system was effectively externally unresponsive. Serverdensity managed to capture the spike and I'm attaching a screenshot of that to this comment (times are GMT+10:00).
I think these spikes generally occur for me on the hour and last roughly the same amount of time if left alone. I have an EBS snapshot job that runs on the hour which I've since moved to 10 mins past the hour to see if that's related--I generally get an error message from that job when spikes happen either about failing to get a response from the snapshot call or failing to get MySQL to lock properly pre-snapshot.