The LPIC-2 Exam Prep i The LPIC-2 Exam Prep 6th edition, for version 4.5 Copyright 2013-2017 Snow B.V. The LPIC-2 Exam Prep ii Copyright © 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017 Snow B.V. Copyright 2013-2017 Snow B.V. The LPIC-2 Exam Prep iii COLLABORATORS TITLE : The LPIC-2 Exam Prep ACTION NAME DATE SIGNATURE WRITTEN BY Written, updated and 2017 reviewed by many, many Snow B.V. colleagues. , Jos Jansen, and Joost Helberg REVISION HISTORY NUMBER DATE DESCRIPTION NAME Copyright 2013-2017 Snow B.V. The LPIC-2 Exam Prep iv Contents 0 Capacity Planning (200) 1 0.1 Measure and Troubleshoot Resource Usage (200.1) . .1 0.1.1 Objectives . .1 0.1.2 iostat .....................................................2 0.1.3 iotop .....................................................3 0.1.4 vmstat ....................................................3 0.1.5 netstat ....................................................4 0.1.6 ss .......................................................5 0.1.7 iptraf .....................................................6 0.1.8 ps .......................................................6 0.1.9 pstree .....................................................7 0.1.10 w .......................................................7 0.1.11 lsof ......................................................8 0.1.12 free ......................................................8 0.1.13 top . .8 0.1.14 htop ......................................................9 0.1.15 uptime .................................................... 10 0.1.16 sar ...................................................... 10 0.1.17 Match / correlate system symptoms with likely problems . 11 0.1.18 Estimate throughput and identify bottlenecks in a system including networking . 11 0.2 Predict Future Resource Needs (200.2) . 12 0.2.1 ........................................................ 13 0.2.2 Monitor IT infrastructure . 13 0.2.3 Predict future growth . 13 0.2.4 Resource Exhaustion . 13 0.3 Questions and answers . 14 Copyright 2013-2017 Snow B.V. The LPIC-2 Exam Prep v 1 Linux Kernel (201) 15 1.1 Kernel Components (201.1) . 15 1.1.1 Key knowledge Areas: . 15 1.1.2 Terms and Utilities . 15 1.1.3 Different types of kernel images . 16 1.1.4 Overview of numbering schemes for kernels and patches . 16 1.1.5 Scheme up to 2.6.0 kernels . 16 1.1.6 Kernel Versioning since kernel version 2.6.0 and up to 3.0 . 16 1.1.7 Kernel Versioning from version 3.0 to 4.0 . 17 1.1.8 Kernel Versioning from 4.0 . 17 1.1.9 XZ Compression . 17 1.1.10 What are kernel modules . 17 1.2 Compiling a Linux kernel (201.2) . 18 1.2.1 Key Knowledge Areas . 18 1.2.2 Terms and Utilities . 18 1.2.3 Getting the kernel sources . 19 1.2.4 Cleaning the kernel . 19 1.2.5 Creating a .config file........................................... 20 1.2.6 make config ................................................ 21 1.2.7 make menuconfig ............................................. 21 1.2.8 make xconfig and gconfig ........................................ 22 1.2.9 make oldconfig .............................................. 25 1.2.10 Compiling the kernel . 25 1.2.10.1 make clean ............................................ 25 1.2.10.2 make zImage/bzImage ..................................... 25 1.2.10.3 make modules .......................................... 25 1.2.10.4 make modules_install .................................... 25 1.2.11 Installing the new kernel . 26 1.2.12 The initial ram disk (initrd)........................................ 26 1.2.13 Manual initrd creation . 26 1.2.14 Patching a Kernel . 28 1.2.15 Removing a kernel patch from a production kernel . 29 1.2.16 DKMS . 29 1.2.17 Dracut . 31 1.3 Kernel runtime management and troubleshooting (201.3) . 31 1.3.1 Customise, build and install a custom kernel and kernel modules . 32 1.3.2 Manipulating modules . 32 1.3.3 Configuring modules . 35 1.3.4 Module Dependency File . 36 Copyright 2013-2017 Snow B.V. The LPIC-2 Exam Prep vi 1.3.5 kmod versus kerneld ............................................. 36 1.3.6 Building A Custom Kernel . 37 1.3.7 /proc filesystem . 37 1.3.8 Contents of /, /boot, and /lib/modules ................................ 37 1.3.9 Tools and utilities to trace software and their system and library calls . 38 1.3.10 The bootprocess . 40 1.3.11 Hardware and Kernel Information . 41 1.3.12 udev . 44 1.4 Questions and answers . 45 2 System Startup (202) 47 2.1 Customizing system startup (202.1) . 47 2.1.1 Key Knowledge Areas . 47 2.1.2 Terms and Utilities . 47 2.1.3 Create initrd using mkinitrd ....................................... 48 2.1.4 Create initrd using mkinitramfs ..................................... 48 2.1.5 Setting the root device . 49 2.1.6 The Linux Boot process . 49 2.1.7 The init process . 50 2.1.7.1 Configuring /etc/inittab .................................. 51 2.1.7.2 The /etc/init.d/rc script . 52 2.1.8 update-rc.d .................................................. 53 2.1.9 Using systemd targets . 54 2.1.10 The LSB standard . 56 2.1.11 The bootscript environment and commands . 57 2.1.11.1 Changing and configuring runlevels . 57 2.1.11.2 The chkconfig command . 58 2.2 System recovery (202.2) . 59 2.2.1 Objectives . 59 2.2.2 Key Knowledge Areas . 59 2.2.3 Terms and Utilities . 59 2.2.4 GRUB explained . 60 2.2.4.1 GRUB 2 . 60 2.2.4.2 GRUB Configuration File . 61 2.2.5 Differences with GRUB Legacy . 62 2.2.6 GRUB Legacy . 62 2.2.7 Influencing the regular boot process . 63 2.2.7.1 Choosing another kernel . 63 2.2.7.2 Booting into single user mode or a specific runlevel . 64 Copyright 2013-2017 Snow B.V. The LPIC-2 Exam Prep vii 2.2.7.3 Switching runlevels . 64 2.2.7.4 Passing parameters to the kernel . ..