Hello, I was looking at some cheap options to expand my capacity, and I am comparing 2 hard drives ST2000DM005 vs ST2000DM008 both seagate barracuda, only difference is that one runs at 5400 RPM and the other at 7200 RPM. Clearly the 7200 RPM model is faster, but my question is that it consumes much more electricity and generates more heat than the 5400 RPM. Does the RPM of a hard disk influence something with the “reputation” or performance of my node?
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Neither. They’re SMR drives (datasheet). Storage nodes have some trouble working efficiently on these drives.
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I think the lower power choice is the right one. Storagenode isn’t hugely intensive on disk or CPU, especially if you are expanding
Caveat: you should move your current data to the SMR drive and let expansion happen on the (presumably) cmr drive. Respect to the comment above.
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SMR drives are terrible at random and sequential I/O, try not using them for holding data.
in regard to the RPM alone there are a few considerations…
the TL;DR version is this
but mainly the RPM will be a question of noise, low rpm = now noise, higher rpm equal better performance and more power draw…
and either will work equally good, tho there might be a special case for high capacity drives.
and now for the details 
7200 RPM - has lower seek time, meaning lower latency and higher iops, slightly higher power usage
5400 RPM - is low noise, and lower power usage, and might also be able to handle movement, as the centrifugal force of the platter will put less force on the bearings when moved.
this doesn’t apply to vibrations i don’t think…
today there is also a 6000 or 5900RPM version or maybe it’s just people writing it wrong… not sure… basically these effects explained is just applied depending on how low or how fast the RPM is…
for disks like 10000 RPM has higher power usage and i’m pretty sure that goes up exponentially the higher the RPM’s get, so a 10000 RPM will use more that then 2800/7200 it takes for it to get to 10000/10000.
a bit simpler and more accurate, 10000 RPM hdd’s are about 50% faster than 7200 RPM drives but will use over 50% more power due to … well physics… lets say… or we could say internal resistance.
heat production i guess might also be a consideration depending how the scales one is considering… as the power usage goes up such things ofc get into play…
and finally you have a size consideration, the larger the disk the larger the storagenode you will or might have on the disk… and since egress is a % of the stored data the storagenode iops requirement for a drive will be higher.
IE Lets say you have a 1TB drive vs a 10TB drive both equal in all ways expect for size.
at first they will both react equally, until the 1TB is filled… then they will start to deviate.
so lets look at the worst end example… we say both nodes / disks are filled…
1 TB drive will see lets say 5% downloads pr month, which will be 50 GB
and
10 TB would be 500GB then with the same 5% downloads…
so without making this more complicated than it needs to be, then the 10 TB hdd will need 800% to 900% more IOPS.
IOPS is the main limitation and one thing the storagenode requires, i’m not sure how much this really comes into play, since i don’t have a high capacity hdd to test it on…
and it certainly won’t be life or death… but could very well affect your storagenode performance long term…
but most likely won’t matter much in the grand scheme of things… but it certainly might… for like say 20 TB drives or such… ofc that also requires you got a 20TB storagenode to put on it, which is a tall order these days…