OpenStack FAQ

FAQ for OpenStack instance e.g. why network on my instance does not work ?

Q: I have launched an Ubuntu instance but I am not able to ssh into the system. I have tried on Windows and Ubuntu host OSs, but I am getting the “Connection Timed Out” error.

A: For accessing the instances from outside world, you need to make sure you have followed these steps:

  1. Your public ssh-key selected (in access and security section) while launching the instance so that you can use it to ssh to the instance.
  2. Assign floating-ip to the instance in order to access it from outside world.
  3. Make sure you have added rules in the security-groups to allow ssh to the instance.

A common issue is to not using a floating-ip to access the instance. You can associate a floating-ip to the instance by clicking “assign floating ip” and then clicking the “+” icon to allocate one if its not available.

Sample video for the same

Q: Unable to perform “sudo yum update” on CentOS user i.e the “Colud not retrieve mirror list” error is thrown.

A: This mostly because the DNS server is not mentioned under the Subnet details.

  1. Go to Network -> Networks, Now click on the network that you setup while creating the instance.
  2. Clicking on the network name will take you to page titled “Network Overview”
  3. On this page find the Subnets section and click on the “Edit Subnets” action button.
  4. Click on the “Subnet Details” section of the dialog that opens.
  5. Enter a DNS Name Server -
  6. Save the changes.

Q: Why do I see too much connection-drop errors? Is there a solution for it?

A: Reason for connection drops and solution