diff --git a/certificates/advanced/ideas.md b/certificates/advanced/ideas.md new file mode 100644 index 0000000..500456d --- /dev/null +++ b/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 diff --git a/modules/qualifying/assets/debian_broken_5.png b/modules/qualifying/assets/debian_broken_5.png new file mode 100644 index 0000000..a15029c Binary files /dev/null and b/modules/qualifying/assets/debian_broken_5.png differ diff --git a/modules/qualifying/assets/debian_broken_6.png b/modules/qualifying/assets/debian_broken_6.png new file mode 100644 index 0000000..e50b9ab Binary files /dev/null and b/modules/qualifying/assets/debian_broken_6.png differ diff --git a/modules/qualifying/assets/debian_broken_7.png b/modules/qualifying/assets/debian_broken_7.png new file mode 100644 index 0000000..d7ae3b1 Binary files /dev/null and b/modules/qualifying/assets/debian_broken_7.png differ diff --git a/modules/qualifying/exercise_broken_machines.md b/modules/qualifying/exercise_broken_machines.md index 7ba0695..2a0ab81 100644 --- a/modules/qualifying/exercise_broken_machines.md +++ b/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) +