In this video, you will look at a couple of more options for troubleshooting. We saw in the previous video that we could use an instance connection, console connection and troubleshoot by getting into a single user mode or troubleshoot the boot options. One more thing you need to remember is when you have an unresponsive compute instance which is not allowing you to connect, you could perform a diagnostic interrupt wherein based on the OS you're using, it will create a crash dump with the logs available and then when you login next time, maybe after, it will result in a crash dump creating under a reboot of the instance and when you login next time, you will have the details about what made it to be unresponsive. A third option; that you have to do some troubleshooting is about attaching a boot volume as a block volume. Attach a boot volume as a block volume. This is an interesting case. Let us say you have a compute instance running, and as you know, every compute instance has its own boot volume and optionally, you can go and attach additional block volumes to it. Now let's say your compute instance is unresponsive, you are not able to login, or the compute instance is not booting up and you tried to console connection and you couldn't figure out what is the problem and you want to look into the contents from a different perspective. What you can do is: you can number one, have another compute instance created. Another compute instance will obviously have its own boot volume. Now, each of the compute instances have their own boot volumes and optionally block volumes attached. Now what you can do is, from the console, shut down the instance which is problem for you, and detach the boot volume from this instance. This is something you will be able to do only when the instance is shut down. How do you do that? You go to a compute instance page, go to the boot volumes section, and you will have an option to detach. Right now it seems enabled, but if you try to detach the boot volume, it will throw an error saying that the instance should be stopped. Now, if you stop this instance and detach the boot volume, then the boot volume is detached from the instance and when a boot volume is detached from a given instance, you can attach it as a block volume to another existing instance. When you do this, you get the benefit of the ability to login to this compute instance with an SSH and look into the contents of the boot volume to troubleshoot. How would you attach? Obviously, this instance, and this instance should be in the same availability domain and if you look at going to attach block volumes and attach a block volume, you will see the option of any block volumes that are available in the same AD and any boot volumes that are currently not attached to any instance, that is why I told you you would have to go and shut down the problematic instance and detach the boot volume, then from any other instance in the same availability domain, you will be able to attach this particular boot volume as a block volume and then go and look into the contents of the boot volume to troubleshoot or do whatever you want that is required. These are additional troubleshooting options you can use to troubleshoot, compute instances.
