整個 migration 的過程是採取不停機轉移，所以 effort 比直接停機轉移高很多：
The main blocker to this easy migration was that Facebook’s private IP space conflicts with that of EC2. We had but one route: migrate to Amazon’s Virtual Private Cloud (VPC) first, followed by a subsequent migration to Facebook using Amazon Direct Connect. Amazon’s VPC offered the addressing flexibility necessary to avoid conflicts with Facebook’s private network.
To provide portability for our provisioning tools, all of the Instagram-specific software now runs inside of a Linux Container (LXC) on the servers in Facebook’s data centers.
所以已經導入 LXC 了...