I'm on a Linode 1080, and the only time I run into any kind of slowdown related to disk access is when I'm doing really nutty stuff with parsing very, very large logs. Those tasks are something I really need to offload to another host anyhow, as it's better to do crunching like that on a separate host and just rsync the results back to the main host upon completion.
What sort of stuff are you doing with your node that appears to be causing high disk consumption? Perhaps there's a way we could help you find a way to reduce it

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