Now let's troubleshoot Azure VM boot failures.
Now, these are never good things to see in Azure, again,
speaking of the fact that we don't have the level of access to the host
hardware that we do with our on‑premises datacenters. You certainly don't
want your Windows Azure VMs to blue screen,
but it happens. Likewise, if you're using Azure Disk Encryption,
you don't want to have a BitLocker recovery screen happen on your Azure VMs.
Well, you might be thinking right off the top, how in the world would I
know? Let's say that my Azure VM is in BitLocker recovery, or let's say
that it is blue screened, how can I verify that?
Well, the answer to that is boot diagnostics. Boot
diagnostics is a property you can enable.
It requires a storage account.
Why?
Because boot diagnostics stores its diagnostics data in
that storage account. Specifically,
you'll find that boot diagnostics periodically takes
console screenshots of the virtual machine.
So you can see on a Windows Server VM that press Ctrl+Alt+Delete to
sign in, which is what you normally want to see. If you're in
BitLocker recovery or blue screen, those states will show up in
those images, all right? Another troubleshooting tool is the
Microsoft Azure Serial Console,
which gives you essentially backdoor console access to your virtual machine,
can be very helpful if the machine is in a blue screen or BitLocker recovery
state. And in order to use Serial Console,
you have to have boot diagnostics enabled first as a
dependency, all right? So again,
we'll look at Serial Console in the demo upcoming. It's
going to give you VM access independent of the network or
operating system state of the VM. It's a very good and important tool for you to have in your tool bag.