Linux System Administration Training

• Delegates should have previously attended the 'QALXESS-2, Linux System Fundamentals' course, followed by several months of practical experience of working with Linux (or have equivalent skills)
• Alternatively, they should have solid experience of administration of any Unix version

At the end of this course you will be able to:

• Compare various Linux distributions
• Understand Linux versus UNIX administration
• Understand the methods and ways of installing a Linux system
• Use the modular kernel architecture and re-configure it to suit a specific need
• Interrogate, manage and configure hardware
• Install additional software: pre-packaged and from source code
• Perform automated software updates
• Configure and troubleshoot boot and operating system start-up process
• Implement and manage partitions and filesystems, including LVM
• Maintain file system security, including using chattr and ACL
• Understand Mandatory Access Control with Selinux and Apparmour
• Enhance user and session security with PAM
• Connect with SAMBA and CIFS
• Use SSH for secure connectivity
• Perform basic network configuration, security and troubleshooting
• Handle packet filtering with iptables and firewalld

Getting Started
Linux server market; Introduction to distributions considered in our courses; Red Hat, Debian (and their derivatives) and SUSE; Understanding kernel versions; Web resources and forums

Preparing For Installation
Understanding PC hard disks: PC hard disk drives: IDE and SCSI; Disk preparation: primary, extended and logical partitions; Understanding memory; Linux swapping and paging: planning swap area, adding swaps; Disk tools: fdisk, parted, hdparm

Installation Methods
Preparing for installation; Installation sources; Selecting system 'personality'; Gathering information; Installation planning and process; Installing Linux from CD-ROM; Post-installation steps; Repeatable installation with installer script

Software Management

• Linux software and source code; Shared and static libraries; Library related tools: ldd, ldconfig; Using 'tarballs' and related tools
• Packages in SUSE, Red Hat and derivatives; Packaging method: RPMs; Package management tools: rpm and yum; SUSE management tool: zypper
• Packages in Debian derivatives; Packaging method - DEBs; Package management tools: dpkg, apt-get, aptitude, tasksel

Boot Management
Bootstrap procedure; Traditional BIOS and MBR; Comparison with modern UEFI and GPT; Using and configuring GRUB 'Legacy' bootloader; GRUB disk numbering; GRUB configuration; Using and configuring GRUB 2; grub2 'global' directives configuration; /boot/grub/grub.cfg; initrd versus initramfs; grub2 tools; Recovering from boot problems; GRUB Legacy vs. GRUB 2 CLI commands

Hardware and Architecture
Types of platforms Linux will run on; Minimum hardware requirements; Selected 3.X onwards features; Supported devices; Configuring sysfs devices with udev; Hardware troubleshooting tools

Kernel Configuration
Kernel runtime parameters; /proc/sys/* and /etc/sysctl.conf; Device drivers in the kernel; Monolithic vs. modular design; Handling modules with lsmod, depmod and modprobe; Creating a customised Kernel; Why rebuild?; Prescriptive sequence of steps; Kernel interesting locations: /usr/src/*, /boot, /lib/modules/$(uname -r)‏

System Service Control
SysVinit startup sequence; Single and multi-user run levels; The init process and its configuration in /etc/inittab; SysVinit startup files (rc files); Systemd method for service control; Units and targets; Configuration files; Using systemctl tool; Integration with SysVinit method

System Logging
Auditing and logging; Basic Unix log files; Simple data tools for working with logs - touch, tail, tail -f, grep; Syslog daemon; Rotating logs; Monitoring logs. Brief Introduction to journald

User Accounts
User-related configuration files: /etc/passwd, /etc/group, /etc/shadow; Creating an account; Basic attributes; Secondary group membership; Password requirement; Customising an account; User home directory; Start-up files

User Account Security, incl PAM
Security aspects of basic accounts; Terminal and shell control files; Testing account usage and activity: lastlog, last, lastb; Identity power as dictated by UID; Role based identity; PAM; User authentication principles; User account control

Extended File Attributes
Recap of basic file and directory permissions: r/w/x, SUID, SGID and sticky bit; File Access Control List (ACL); Making use of individual user and group assignments; Understanding mask property; Using setfacl and getfacl of files and directories; Applying additional file attributes through chattr; Using chattr to set additional attributes; Applying privileged attributes; Using lsattr to explore extended attributes

Managing Filesystems
Linux native filesystems: ext*, reiserfs, xfs, btrfs ; Configuring filesystems; Performance - mkfs command; Security - mount command; Troubleshooting and diagnosing filesystems: fsck, tune2fs, debugfs, fuser, dumpe2fs, xfs*; Restricting disk assignments with user/group

Storage Management with LVM
Overview of disk partitioning; Using fdisk to create physical partitions; LVM structure: PV, VG, LV; Logical volumes must have filesystem created; Standard mkfs, mount and /etc/fstab treatment applies; Logical volumes can be dynamically resized

Networking Infrastructure
Number crunching; Network related files and directories: interface configuration files, name resolving; Modern tools - the ip and ss command: general syntax and usage; Network parameters in the kernel; Configuring proxy; Static routes; Interface parameters with ethtool; Interface bonding: modes and configuration

Perimiter Network Protection
Firewall concepts; Infrastructure and DMZ; Types and implementations; Kernel's role; Network parameters in /proc/sys/net; NetFilter module; Linux firewalls: iptables and firewalld; Understanding firewalld zones and firewall-cmd tool; Alternatives products: IPCop, Shorewall, ufw and many others...; knockd to open holes in your firewall on demand

Introduction to SELinux
DAC vs. MAC security policies; Problems with traditional, discretionary, methods; Products providing mandatory access methods; Main SELinux features; Policies, enforcements, control; Scope, coverage and availability; SELinux configuration and management; SELinux states; Labelling and access policies; Policy database and run-time flow; Modifying existing, and creating new, policies

Network Services
Protocols & Services; Network super-daemons: inetd, xinetd ; TCP wrapper with tcpd; Network time protocol; Hardware vs. software clock; Daemons and configuration

Samba and CIFS
What is Samba; SMB and CIFS protocols; Installing and configuring Samba components; Configuration file: /etc/samba/smb.conf; Special and user sections; Configuring the [global] section; Samba daemon and diagnostic tools: smbd, nmbd, smbstatus, testparm, SWAT; Samba client tools: nmlookup, smbclient, smbtree, smbtar; Viewing Samba shares in Windows;

SSH Hints and Tricks
SSH purpose; Recap of basic SSH use; SSH client and server configuration ; Using SSH keys; Creating public/private key pair; Configuring and using SSH agent; Tunnelling X application in SSH; Port forwarding; Principles of local and remote port forwarding; Forwarding through a firewall and multiple gateways