In this lesson, you'll learn more about Systemd UDFD.
So when alerted by the Linux kernel, Systemd UDFD will initialize new devices.
And this involves writing device information to slash sys so that the complete device can
be tracked and the device parameters can be administered.
And also creating device notes in the slash dev directory so that there is a user interface
that allows users to communicate with the device.
It can be convenient to track this procedure using the UDFADM monitor command.
That will trace every single step and it will show you in detail what is going on.
And that can be convenient to troubleshoot.
If ever you connect a device and nothing is happening, well, UDFADM monitor is giving
deep level insight.
You can also get more detailed information about devices using UDFADM info.
Minus minus name is dev note.
As in UDFADM info, minus minus name is dev SDA.
Let me show you.
So to start it, I'm using UDFADM monitor.
And there you can see that monitor will print received events for UDF and for the kernel.
So the kernel is the actual device event.
And UDF is related to the rule processing.
Let's plug in USB thumb drive.
So here you can see that a lot of output is generated.
And if you scroll up in the output, you can see some stuff that is actually interesting.
So it starts by the kernel that is adding a device.
And the device was found on this specific PCI address.
And that is resulting in UDF checking if there's any rules to be processed.
Then a little bit further, you can see that drivers are involved, the USB storage driver.
And this USB storage driver is implemented by the USB storage module.
The UAS module is involved.
And you can see that more drivers are loaded.
And based on the presence of a new driver, additional steps can be taken.
And then a lot later, here we can see that the block device is added, block dev SDA.
And on the block device, we can see right here that the partition was detected.
And the result, well, the result should be visible in LSBLK.
LSBLK, which is list block device.
And in this list block device, we can see that the SDA block device has successfully
been added.
Now in these devices, there is a lot of information that is stored.
You can find that information using UDF ADM info.
Minus minus name is slash dev slash SDA1, for instance.
And here we can see all the device parameters that have been discovered.
And these device parameters can be used in UDF rules.
In the next video, you'll learn a bit about UDF rules.