Advanced Linux Administration

Overview

Linux administration involves a fair amount of interaction with system hardware and the kernel, as well as using proliferation of front end tools. This course provides a hands-on approach to these and other advanced administrative tasks that are unique to Linux, concentrating on CLI-based methods.With its distinctive design approach, this course is also suitable as a Unix to Linux conversion for existing Unix administrators. It is a fast-paced skills-building event, full of practical exercises and troubleshooting.
The course platform will be one of the Red Hat derivatives, such as CentOS or ScientificLinux. However, the discussions and material address every major Linux strand, and wherever specific tool, technique or method is relevant, SUSE, Debian and Ubuntu specifics are covered. For example, we discuss the unique approach adopted by various systems in the areas such as system start-up and software management.

Target audience

All existing administrators, developers, analysts, indeed, all users who find themselves looking after a Linux box. Also, experienced Unix Administrators who need to port their skills to Linux.

Prerequisites

• Delegates should have previously attended the Essentials of Linux Administration 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

Delegates will learn how 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
• 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
• Enhance user and session security with PAM
• Perform basic network configuration and troubleshooting
• Configure network services with inetd/xinetd and tcp wrappers

Course Outline.

Getting Started
Course pre-requisites; Introduction to flavours considered in this course (Red Hat, SUSE, Debian); A look at Linux administration; Interesting Linux directories; Making the best of the /proc filesystem; GUI front-end administrative tools: system-config* in RHEL; yast in SUSE; Generic administration tool: WEBMIN

Preparing For InstallationUnderstanding 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 MethodsPreparing 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 Package; Packaging in Red Hat and SUSE; Packaging in Debian and Ubuntu; Installing, checking status and removing packages; Installing software supplied as source code; Handling kernel patches; Automatic software updates; Using yum in Red Hat and SUSE; Using APT tools in Debian and Ubuntu

Boot ManagementBootstrap procedure; Master Boot Record (MBR)‏; Using and configuring GRUB bootloader; Grub disk numbering; Grub configuration; Recovering from boot problems

Hardware and ArchitectureTypes of platforms Linux will run on; Minimum hardware requirements; Selected 2.6 features; Supported devices; Configuring sysfs devices with udev; Network interface considerations: configuration, bonding; Hardware troubleshooting tools

Kernel ConfigurationKernel numbering; Kernel interesting locations - usr/src/linux, /boot, /lib/modules/$(uname -r); Creating a customised Kernel - Why rebuild? Prescriptive sequence of steps; Modifying kernel parameters

Start-up and ShutdownSingle and multi-user run levels; System start-up files (rc files) -/etc/rc.d/rc.* directories; Linux specific files - /etc/rc.d/rc.sysinit and /etc/rc.d/rc.local; Activating services on demand - GUI or command line? Start-up specifics in SUSE, Debian and Ubuntu

Managing Logs
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.

User AccountsQuick recap of for user account requirements; Standard configuration files (group, passwd, shadow); User account specifics under Linux - Private groups, /etc/gshadow file, Using chage for controlling password ageing; Listing account information; User quotas - Configuring aquota.user and aquota.group files.

PAM and user account securityUser types and their accounts; Superuser(s), daemon users, ordinary users; Terminal and shell control files; Unknown and dormant accounts; Testing account usage and activity: lastlog, last, lastb; Authenticating with PAM: PAM structure, control flow and configuration; User login and security files: login.defs, securetty, messages

Managing FilesystemsLinux default filesystems - ext2, ext3, ext4; Filesystem features and constructs - i-node tables, directories and links; Configuring filesystems - Performance - mkfs command - Security - mount command; Troubleshooting and diagnosing filesystems - fsck, tune2fs, debugfs, fuser; Restricting disk assignments with user/group quotas

Storage Management with LVMPhysical partitions declared as physical volumes (PV); Physical volumes added to volume groups (VG); Volume groups split into logical volumes (LV)

Extended File AttributesRecap 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

Networking InfrastructureNumber crunching; Network related files and directories: interface configuration files, name resolving; All-in-one network interface tool - the ip command: general syntax and usage; Network parameters in the kernel; Static routes; Interface parameters with ethtool; Interface bonding: modes and configuration

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