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Does Fly implement live migration under the hood?

• michaeldwan 4y ago
  If you mean moving (or copying) VMs to another region/host, sorta. Stateless compute is easy; our apps platform (orchestrated by Nomad) already does it. Volumes complicate things because they live on a specific host, and moving volumes between hosts is a slow and tedious process. Solving this is high on our priority list. We need super fast volume forking and host migrations like yesterday.
  • dilyevsky 4y ago
    Yeah I was referring to VM snapshot transfer vsphere/openstack/gcp instance style. > our apps platform (orchestrated by Nomad) already does it Preserving internal vm state or just restart everything?
    • michaeldwan 4y ago
      Ah! I've had volumes on the top of my mind all week... Firecracker supports snapshots in a dev preview but we're not using it yet. We can't really do anything like that on Nomad, which is one of the many reasons we're keen to get off it.
• mrkurt 4y ago
  We do not. I'd like to, but we have a lot more infrastructure work to do before it's even possible. At the moment, we don't even migrate persistent disks or IP addresses between hosts.
  • dilyevsky 4y ago
    Interesting, I can see Firecracker doesn’t even support snapshotting it seems which could be a challenge
    • ignoramous 4y ago
      In the works, apparently: https://github.com/firecracker-microvm/firecracker/blob/main/docs/snapshotting/snapshot-support.md https://github.com/firecracker-microvm/firecracker/blob/main... LayerCI / WebApp.io did mention they migrate VMs... Fly.io should steal that tech https://news.ycombinator.com/item?id=25980897 https://news.ycombinator.com/item?id=25980897