[jedberg]

You don't have to move all the data, but you have to constantly move the needed data back and forth, unless you store a second copy in the cloud. And then you have to start capacity planning again.

> This isn't how I've seen the numbers work out for the huge chunk of workloads that require mostly static instances.

Any time someone says this I have to question if they really looked at the "all in" number. Did you include the salary of the person in purchasing who orders the servers? Did you include the lost engineering time dealing with dead servers (instead of just shutting them off)? Did you include the cost of spare hardware sitting around for emergencies? Did you include the cost of downtime due to broken hardware while waiting for it to be repaired or replaced?

There are so many other costs to running your own datacenter besides the servers and the space, which Amazon gets to amortize over all their customers, but you have to bear 100% on your own.

[secabeen]

>There are so many other costs to running your own datacenter besides the servers and the space, which Amazon gets to amortize over all their customers, but you have to bear 100% on your own.

Yes, but those costs may be low (or zero) for you, but Amazon has to architect at a level much higher than that. For example, I have researchers with data that has zero backup/DR requirements. This is 10s of TB of data, but if they lost it all due to a fire or a catastrophic system crash, they would just shrug, order a new storage array from the insurance money, and request new copies of the data from the research labs at other institutions that also have it. Amazon doesn't offer any storage products at that reliability level, and the ones that are even close have significant data access latencies or file transfer costs to run analysis over a significant chunk of the data.

So, they buy a basic NAS, stuff if with 12T drives, and pay $0.19/Gig for it. That's one time, not monthly, and at only 50% utilization. Assuming S3 Reduced Redundancy is $0.02/Gig/mo (it's actually a little more, but we're being generous), they start saving money in month 10 not counting the data transfer or compute costs associated with processing that data either locally or in the cloud.

[apple4ever]

> Any time someone says this I have to question if they really looked at the "all in" number.

Yes we did. > Did you include the salary of the person in purchasing who orders the servers?

That's a one time cost, and very low.

> Did you include the lost engineering time dealing with dead servers (instead of just shutting them off)?

Of course- but AWS has higher engineering costs to make it work, so self-hosting comes out in the end.

> Did you include the cost of spare hardware sitting around for emergencies?

You don't really need spare hardware. You have redundancy and get same day service from your vendors. And hardware nowadays rarely fails.

> Did you include the cost of downtime due to broken hardware while waiting for it to be repaired or replaced?

That would be zero, because a properly designed system has no downtime.

> There are so many other costs to running your own datacenter besides the servers and the space, which Amazon gets to amortize over all their customers, but you have to bear 100% on your own.

Sure, but there are so many other costs to running on Amazon that aren't there with self hosted.