We've got problem with a very serious repetitive incident on our core system. Namely, cpu load spikes to 300-400 and the whole db becomes unresponsive. From db point of view nothing special is happening, memory looks fine, disks io's are ok and the only problem is huge cpu load. Kernel parameters that are increasing with load are always the same:
Can you provide output of `iostat -myx 10` at the “peak” moments, please?
Also, it'd be good to look in more detailed bgwriter/checkpointer stats.
