AWS Singapore kindly gifted http://hackerspace.sg/ with 500SGD of AWS credits.

Since the mirrors http://mirror.nus.edu.sg/ and http://download.nus.edu.sg, which are two separate competing groups from the NUS which oddly try to outdo each other in incompetence, have had several issues mirroring Archlinux in my two year experience of using either of them, I thought lets use these credits to host an Archlinux mirror!!

After much head scratching with the AWS jargon of {ebs,s3} and {hvm,paravirtual} EC2 Archlinux images, I launched an “ebs hvm” instance of m3.xlarge.

I got a nice 80GB zpool going for the mirror and everything was looking good. However, now to do the budgeting.

On demand pricing is $0.392 an hour

There is roughly 9000 hours in a year. So that’s $3528. Eeeek, over budget by just 3000 dollars!

Ignoring added complexity of Spot and EBS enhancements, a one year resevered instance under “Light Utilization Reserved Instances” (I am not sure what that means) is 497 dollars! Yes!!

I’m told “Light utilization means that you will not turn it on all the time”. For 1 year I would need heavy utilization!

So a m3.xlarge would be: 981 (down payment) + 24 * 365 * 0.124 = $2067.24, about 1500 dollars over budget.

Oh and bandwidth?

Well, a mirror is going to be a network whore. AWS charges for bandwidth. I tried their calculator (since I couldn’t figure out what they charge per GB) with a lowball 1TB a month in and out and that costs almost 200USD.

Wow that’s expensive! AWS EC2 (+ 500SGD credit) isn’t suitable for an Archlinux mirror! :(

Digital Ocean quote

For a machine with at least 50GB of disk, you would need Digital Ocean’s 60GB offering, with

• 4GB / 2 CPUS
• 60GB SSD DISK
• 4TB TRANSFER

So that is 40USD a MONTH or 480USD a year. A lot cheaper than EC2, and bandwidth clearly priced at 2c per GB, so 1TB = 20USD IIUC.

Lessons learnt

Running a mirror is quite expensive on EC2. It’s not really feasible on DO either without some free unmetered traffic.