Moving IP during emergency maintenance
Linode
Linode Staff
Hi,
Let's say we have a linode A with ip address X, which requires emergency maintenance and you are migrating it to a new host within the same data center.
Let's say we have an external checker that health checks the linode A and if it becomes unresponsive, we create a new linode B with ip address Y from the last backup of A and swap ips between A and B. (all via API)
So the result of these manipulations will be A with ip Y and B with ip X.
In the maintenance description you say that once the linode has been migrated it will keep the original ip.
Question - what ip will be assigned to the migrated linode A after the migration has been completed. (Given that our health checker did all the API stuff before you have finished the migration)
1 Reply
asilverman
Linode Staff
Great question! I did a little bit of testing. First I want to explain the migration process, then my findings. But yes it does work.
When we have emergency maintenance. The process entails that when migrate a few Linodes off the host at a time. While they are waiting depending on the problem with the host the Linodes should be waiting in line to migrate. Once it is the Linode's turn to migrate, the process will start.
I tested this process while waiting in line to migrate and during the migration process. The IP was able to switch without giving me any errors both times. This may not work 100% of the time. It will depend on the reason for the emergency maintenance.
We do have an IP Failover feature in the Linode Manager. Which will know to move the IP over if your Linode become unresponsive.
Also if high availability is important we have a guide that will explain many of the options available.