In general that's my theory also (that after the initial fill, and maybe after an initial "data churn" we might power them down). However, a full pod often has at least one file from several hundred thousand individual customers. If any one of those customers prepares a restore, those drives have to be spinning. Also, we now have an iOS and Android app that you have access to all your files on your laptop from the convenience of your Smartphone - which again means the drives have to be spinning.
> Are you worried about the stresses induced by spin up/down and thermal variations?
Absolutely. Our datacenter techs are convinced that if they swap a drive QUICKLY the pod has a higher chance of coming back up without any problems, if they let the pod get entirely cool it statistically seems to have more problems when it comes back up - a full cool down and heat up seems to cause issues.
> Are you worried about the stresses induced by spin up/down and thermal variations?
Absolutely. Our datacenter techs are convinced that if they swap a drive QUICKLY the pod has a higher chance of coming back up without any problems, if they let the pod get entirely cool it statistically seems to have more problems when it comes back up - a full cool down and heat up seems to cause issues.