Is it useful to deploy OpenStack to a single node?

peter asked:

Due to several limitations and only few and expensive offers of Windows-based dedicated servers, I thought about renting a Linux server instead and running even multiple VMs on that server.

I thought about using KVM, however it is not trivial to set up and run a new VM in the command line (not difficult, just that it isn’t few clicks). I had access to an OpenStack-cluster and it was really easy to deploy new machines, so also colleagues of mine would be able to do it.

The problem is, that for now we’ll have only one rented server, and those servers have only one physical network. I’ve found a script which would set up all OpenStack-services on one machine (, but is it useful to do this? Or should I just stick with KVM directly, since I’ll have there anyway only 1 maximum later on a second machine with 5-10 VMs and the OpenStack overhead would be just too large?

Or is there something like the virt-manager as an online tool? This way creating and running VMs would be also simplified.

My answer:

OpenStack will run fine on a single machine, and this is indeed a useful setup in scenarios like evaluation or developing OpenStack itself. A tool called PackStack, which is available on RHEL variants, makes it pretty easy to deploy.

But OpenStack is probably overkill for your scenario, unless you plan to expand to multiple physical servers in the future. If this is the case, you should take the time to get OpenStack up now, which will make expanding easier in the future.

If you don’t plan to expand, then just using straight up KVM (with libvirt?) is fine. You can run virt-manager on your desktop and manage the remote machine with it. It automatically sets up an ssh tunnel to the remote machine to do this. Note that you have to place your ssh public key in the authorized_keys for root on the remote server in order to do this, and set PermitRootLogin without-password instead of no on the server’s ssh daemon.

And if circumstances change later, it’s pretty easy to import KVM virtual machines into OpenStack.

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