Hi all,
I set up an AWS EC2 cloud Tor relay a month ago and made an expensive mistake. Perhaps others may learn from my example!
I followed the instructions on the tor-project website, and found that it actually is quite a simple process, as it says. I did notice that the AWS setup screens I was seeing were different from the screenshots on the website, but they were asking me similar questions so I just went with the defaults where the website said "No changes". I didn't look closely enough.
Everything went to plan and I watched the relay work for a month. However, on the AWS EC2 Management console I neglected to click on "Services" then "Billing" to see how much they were charging me.
At the end of the month I got a bill for 120 dollars. And Amazon were quite right - they were charging me for the 1024 GB of storage I had accidentally asked for by not changing the default when I set up the instance. The first 30 GB were free, the other 994 I was paying for. And I was only actually using 1.5 GB ...
There doesn't seem to be any way of shrinking the storage of an existing instance (though it can be expanded, now, with EBS, Elastic Block Storage), so I had to terminate it (which deletes the storage) and create another instance with a more reasonable 10 GB (of which df tells me I'm now using 11%).
So ... if you've recently set up an AWS EC2 cloud relay with the Tor AMI, check your storage, and your billing!
I think the option to specify your storage amount (with its default of 1024 GB) may have been introduced when AWS introduce EBS instead of just instance-backed storage (which may have defaulted to the size of the AMI??).
In any case, I think the tor-project website AWS screenshots urgently need to be changed to reflect the current setup procedure, with a warning not to accept the 1024 GB default and an explicit recommendation about the amount of storage to ask for (was my guess of 10 GB reasonable?).
Oh well, I have gained 100 dollars worth of wisdom from the episode. My way of "Don't look too closely, and hope for the best at the end of the month" was *not* a good idea.
Nick Sheppard