updates the broken machines doc

certificates/advanced/ideas.md

@@ -0,0 +1,34 @@
+# Hardware 
+
+* compare `/proc/interrupts` between a physical machine, a VM and a Raspberry Pi
+* compare `/proc/ioports` between a physical machine, a VM and a Raspberry Pi
+* compare `/proc/dma` between a physical machine, a VM and a Raspberry Pi
+* install a physical machine, first with BIOS, next with UEFI via debian expert install
+* inspect the link between `kernelspace` and `userspace` via `strace`
+* learn about device ID's via `udev` rules
+* manage hdd's in a VM to explore SATA, SCSI, etc
+* install debian on a LVM and expand with a second disk
+* add a new hdd after installation, format, mount it and add it to fstab
+
+# Booting
+
+* replace systemd with sysV
+
+# Topic 103: GNU and Unix Commands
+
+* explore different shells
+* basic regex exercises
+* vim regex exercises on html/md files
+* sed exercises for multiple files
+
+# 103.5	 Create, monitor and kill processes
+
+* deep dive into htop with strace and lsof
+* use ps and pgrep for scripting purposes
+* practical usage of `nice` with compilation tests
+* `nohup`
+
+# 104.6	 Create and change hard and symbolic links
+
+* git dotfiles with symlinks
+* nginx sites-enabled vs sites-available

modules/qualifying/exercise_broken_machines.md

@@ -1,10 +1,12 @@
 # Broken Machines
 
 Over the coarse of my Linux career I broke quite a few machines.
-Hopefully you can fix them for me.
+Hopefully you can fix these for me.
 The username and password of the first account created is isib/isib unless mentioned in the exercise.
 
-## Broken Machine 1
+## GRUB problems
+
+### Broken Machine 1
 
 I messed up and forgot to install grub during the Debian installation.
 Can you find a way to fix this for me please?
@@ -12,21 +14,77 @@ Thanks!
 
 ![broken 1](./assets/debian_broken_1.png)
 
-## Broken Machine 2
+#### Tips
+
+How did this happen?
+Well, you probably encountered the *black screen of death* on one or more Linux VM's yourself.
+When at the very last stage of the Debian installation you forget to install GRUB you created this problem yourself.
+The installation is complete and functional but the system has no way of booting.
+There are a lot of different approaches to fix this but they all boil down to the same solution.
+You need to install GRUB on the MBR of the HDD `/dev/sda`.
+
+Luckily there are dedicated live disk images (ISO's) to fix this.
+I would recommend having a look at [supergrub2](https://www.supergrubdisk.org/).
+
+### Broken Machine 2
 
 This machine seems to boot into `htop` and nothing else!
 There must be a way to fix this without having to reinstall the machine.
 
 ![broken 2](./assets/debian_broken_2.png)
 
-## Broken Machine 3
+#### Tips
+
+Your GRUB configuration is causing this!
+Luckily by default GRUB offers a *recovery mode* in it's *advanced options*.
+This will drop you into a shell where you can fix the configuration file I messed up.
+
+### Broken Machine 3
 
 Not `htop` again!
 
 ![broken 3](./assets/debian_broken_3.png)
 
-## Broken Machine 4
+#### Tips
+
+I said *by default* before no?
+Well, here the *recovery mode* is missing so you'll have to find a way to override the `init` parameter of GRUB so you can get a shell to fix what I messed up.
+
+### Broken Machine 4
 
 I forgot my password...
 
 ![broken 4](./assets/debian_broken_4.png)
+
+#### Tips
+
+Overriding the `init` parameter in GRUB is a classic Linux hack.
+If you have physical access to a Linux machine you can gain `root` access with the following method.
+The easiest way to protect a machine form this attack is to do full disk encryption or to set a GRUB password.
+
+
+## Disks and problems
+
+### Broken Machine 5
+
+Somebody erased the MBR from the HDD.
+Can you put a new one on there?
+Don't forget to install GRUB again once the HDD is fixed.
+This is a tricky one but there are quite a few tutorials online to help you out.
+
+![broken 5](./assets/debian_broken_5.png)
+
+### Broken Machine 6
+
+The root partition is pretty much full but the disk is big enough to house more data.
+Can you please enlarge the disk so we can comfortably use the machine again without running into `no space left on device` issues?
+
+![broken 6](./assets/debian_broken_6.png)
+
+### Broken Machine 7
+
+The install works but the root partion is rediculously small.
+Luckily the installation was done on a LVM volume so we can add more disks to it!
+
+![broken 7](./assets/debian_broken_7.png)
+