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Installing Ubuntu OpenStack requires at least five machines with two disks, two of which have two network interfaces (NICs). Install Ubuntu Server on one of the machines with two interfaces.

Why do I need two disks? What if I have 5 machines with 2TB capacity each but on a single disk? Would this setup not work i:e http://www.ubuntu.com/download/cloud/install-ubuntu-openstack? Why do we need 2 interfaces on two machines? I understand for one machine, one interface connects to the internet and the second to the local network. But why do we need 2 interfaces for the second machine?

0xF2
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Umair Chaudhry
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  • Would it not be better to ask this on https://ask.openstack.org/en/questions/ This claims it can be done with 1 NIC: https://ask.openstack.org/en/question/2133/openstack-single-node-single-nic/ – Rinzwind Aug 04 '15 at 12:30
  • This question is about the Autopilot. If you are doing things manually, more configurations are possible — but you need work them out on the shell, with no easy automation. – 0xF2 Aug 05 '15 at 07:57
  • The requirement is now 5 machines, no longer 7, per http://www.ubuntu.com/download/cloud/install-openstack-with-autopilot. Updating the question to reflect change. – 0xF2 Jan 05 '16 at 17:31

1 Answers1

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Multiple disks are required because the OpenStack configuration deployed by the Autopilot co-locates the Nova Compute service and Ceph on the same nodes. This results in one disk being used for system boot, and one being allocated to the Ceph OSD for data storage.

You get scale-out storage and scale-out compute in the bargain, but you need two disks.

You could substitute USB keys for the second drive... I would not call that "production" but it is a quick workaround for trying out things.

0xF2
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  • Substituting it with a flash drive? would 16 gigs or 8 gigs be enough for that? In case I do substitute it with a flash drive, each time i disconnect the flash and reconnect it, would it require reconfiguration of ephemeral/Ceph disk? – Umair Chaudhry Aug 06 '15 at 21:46
  • Right, if you use a flash drive, you just leave it plugged in permanently. Get a low profile model, like the SanDisk 32GB ones. – 0xF2 Aug 06 '15 at 23:39