And yes, look at this, the end of another module,
a module where you're progressing further, where you're learning more, and
where you're able to do far more within your job role.
We've looked at booting Linux, and that involves in our GRUB bootloader,
the Grand Unified Bootloader, which is pointing through to our Linux kernel
and our initramfs. It's this RAM filesystem that contains the drivers to
allow the kernel access to the root filesystem.
When we're looking at configuring GRUB, we have our default file,
/etc/default/grub, and we looked at changing things such as
the timeout and also looking at how the prefixes were
obtained from our system release file.
Having changed the configuration though,
we can create a new configuration using the grub2‑mkconfig. If we
prefer, though, not to recompile our configuration,
we can look at the grubby configuration tool, and with this, we
can make changes to the running configuration. And we saw that
we could do this to all kernels or a specific kernel entry that
we wanted to change.
When we take a look at recovering from kernel panics,
we could see that we could create a kernel panic by having
a corrupt or an inaccessible initramfs.
This was going to cause the error where the kernel cannot access the
root filesystem. To recover from this, we could boot to a rescue
system or any other live menu entry system that we have within our
GRUB menu. Having booted up,
we can create then a new RAM filesystem with the
mkinitrd command or the dracut command.
But hopefully that taught you a lot about the files that are involved
during the boot process, so GRUB, the kernel, and the initramfs and look
at all ways that we can tune our environment, so it works more the way
that we need. With this done and dusted, we're ready though to move on to
our next topic, and that's going to be taking a look at managing the Linux
network configuration, and I do look forward to seeing you in that module very soon.