http://rockhopper.monmouth.edu/cs/jchung/ 2026-04-07T03:38:28+00:00 http://rockhopper.monmouth.edu/cs/jchung/ http://rockhopper.monmouth.edu/cs/jchung/_media/wiki/logo.png text/html 2013-04-01T23:04:05+00:00 Anonymous (anonymous@undisclosed.example.com) http://rockhopper.monmouth.edu/cs/jchung/cs471/cs-471_sp13_useraddpw?rev=1364857445 The useraddpw script of Assignment 4 #!/bin/bash userid=$1 password=$2 # Generate encrypted hash of $password: hash=$(echo $password | openssl passwd -1 -stdin) # Create user account for $userid while assigning $hash as password: useradd -m -p $hash $userid text/html 2013-04-01T23:06:51+00:00 Anonymous (anonymous@undisclosed.example.com) http://rockhopper.monmouth.edu/cs/jchung/cs471/cs471_mail_here_shell_function?rev=1364857611 Example script that uses a “here doc” in a mail function: #!/bin/sh mail2local() { user=$1 # $1 is the 1st argument passed to the function pw=$2 # $2 is the 2nd argument passed to the function # Send mail using a "here document". # The terminating "END" must not be indented. mail -s "Welcome new user!" $user@localhost << END Welcome $user to your new UNIX account. Your password is $pw. Change it soon. END } # Call mail2local function with enemeth and unixf001 as ar… text/html 2018-02-23T19:42:13+00:00 Anonymous (anonymous@undisclosed.example.com) http://rockhopper.monmouth.edu/cs/jchung/cs471/cs_471_-_basic_process_management?rev=1519414933 Controlling Processes * process priorities * normal user process priorities range from 0-19 * called “niceness” of a process, where 0 is normal and 19 is nicest * root and user can control priority of processes * root process priorities range from -20 to 19. text/html 2018-03-23T23:43:39+00:00 Anonymous (anonymous@undisclosed.example.com) http://rockhopper.monmouth.edu/cs/jchung/cs471/cs_471_-_configuration_management?rev=1521848619 Configuration Management ---------- UNIX and Linux System Administration Handbook (5th Ed., chapter 23, p. 833): “Configuration management software automates the management of operating systems on a network. Administrators write specifications that describe how servers should be configured, and the configuration management software then text/html 2018-03-23T01:16:12+00:00 Anonymous (anonymous@undisclosed.example.com) http://rockhopper.monmouth.edu/cs/jchung/cs471/cs_471_-_configuration_management_with_puppet_supplement?rev=1521767772 Configuration Management with Puppet Getting Started - We'll get started with puppet by visiting http://www.debian-administration.org/articles/526. - Next, we'll attempt a tutorial involving ntp at <http://bitfieldconsulting.com/puppet-tutorial>. - After that, we'll attempt a tutorial involving user accounts at <https://www.linux.com/learn/introduction-puppet-streamlined-system-configuration> ---------- Details 1 - Enabling puppetmaster/puppet (server/client) communication text/html 2013-02-25T15:02:20+00:00 Anonymous (anonymous@undisclosed.example.com) http://rockhopper.monmouth.edu/cs/jchung/cs471/cs_471_-_daemon_processes_supplement?rev=1361804540 ---------- * Before doing anything else, you will need to install the build-essential package on your virtual Linux system with apt-get install build-essential. * We will follow the Linux Daemon Writing HOWTO at <http://tinyurl.com/5ert3u> ---------- text/html 2018-04-20T20:21:35+00:00 Anonymous (anonymous@undisclosed.example.com) http://rockhopper.monmouth.edu/cs/jchung/cs471/cs_471_-_email_networked_file_systems_system_file_sharing?rev=1524255695 Email, Networked File Systems, System File Sharing ---------- Electronic Mail * An essential service * Email jargon: mail user agents (MUAs), mail transport agents (MTAs), retrieval agents, delivery agents ---------- Mail user agents (MUA) text/html 2018-04-06T18:18:51+00:00 Anonymous (anonymous@undisclosed.example.com) http://rockhopper.monmouth.edu/cs/jchung/cs471/cs_471_-_general_sysadmin_principles?rev=1523038731 Some General SysAdmin Principles ---------- Documentation * Document your work. * Keep a journal. * Use at least a plain text file. * Date each entry. * If you have a boss that you send your journal to, spellcheck your journal. * text/html 2018-01-19T20:48:36+00:00 Anonymous (anonymous@undisclosed.example.com) http://rockhopper.monmouth.edu/cs/jchung/cs471/cs_471_-_introduction_unix_installation?rev=1516394916 Introduction, Installation ---------- Introduction, Discussion of Course Content ---------- What is a [UNIX System] Administrator? Noun: 1. One who administers; one who manages, carries on, or directs the affairs of any establishment or institution. text/html 2013-04-25T13:50:10+00:00 Anonymous (anonymous@undisclosed.example.com) http://rockhopper.monmouth.edu/cs/jchung/cs471/cs_471_-_kernel_tuning_printing?rev=1366897810 The Kernel, Tuning, Printing ---------- The Kernel and Kernel Configuration * The OS kernel provides interfaces to the following * Processes (time-sharing, protected address space) * Signals (to/from processes) * Interprocess communication (pipes and network connections) text/html 2018-01-24T21:49:25+00:00 Anonymous (anonymous@undisclosed.example.com) http://rockhopper.monmouth.edu/cs/jchung/cs471/cs_471_-_monitoring_i?rev=1516830565 Basic Monitoring ---------- text/html 2018-02-02T19:15:54+00:00 Anonymous (anonymous@undisclosed.example.com) http://rockhopper.monmouth.edu/cs/jchung/cs471/cs_471_-_os_bootup_and_services?rev=1517598954 Boot Up/Shut Down, Services ---------- * See General SysAdmin Principles on Startup/Shutdown ---------- ---------- Some Review Who, What, Where? * The system administrator (SA) is often required to maintain multiple systems and may have different login IDs on those systems. * The systems themselves may be different in terms of operating system, architecture, etc. text/html 2013-02-19T04:03:07+00:00 Anonymous (anonymous@undisclosed.example.com) http://rockhopper.monmouth.edu/cs/jchung/cs471/cs_471_-_ping471_script?rev=1361246587 ping471 system monitoring script ---------- Developed in class on Mon 2/11/13: #!/bin/sh # Ping (fping) my hosts in HH 310 for CS-471. # Display hosts that don't respond. for each in chung cslin01 cslin02 do /usr/sbin/fping -q $each.monmouth.edu || /usr/sbin/fping -q $each.cs.monmouth.edu || echo $each not responding. | mail -s "ping471 alert" jchung@monmouth.edu done text/html 2018-02-23T19:41:57+00:00 Anonymous (anonymous@undisclosed.example.com) http://rockhopper.monmouth.edu/cs/jchung/cs471/cs_471_-_processes_users_software?rev=1519414917 Users and Limits ---------- Users & Groups * See the section of General Admin Principles that deals with Users. Becoming root vs. Running as root (su, sudo) See Types of Users. Becoming root * Use su or su - or su - root * Can also use su to become a normal user, e.g., su - jchung text/html 2013-02-07T14:57:27+00:00 Anonymous (anonymous@undisclosed.example.com) http://rockhopper.monmouth.edu/cs/jchung/cs471/cs_471_-_review_of_scripting_and_the_shell?rev=1360249047 ---------- Conditional command chaining is often used in scripts. Are the following code blocks equivalent? Code block 1: if [ ! -d /tmp/winders-in-use ]; then /home/vmwin1/bin/vmwinoff # vmwinoff is a shell script fi Code block 2: [ ! -d /tmp/winders-in-use ] || /home/vmwin1/bin/vmwinoff text/html 2018-04-17T20:15:12+00:00 Anonymous (anonymous@undisclosed.example.com) http://rockhopper.monmouth.edu/cs/jchung/cs471/cs_471_-_security_logging_backups?rev=1523996112 Security, Backups, Logging ---------- * See General SysAdmin Principles on Security and Backups ---------- Security Some Security Breach Examples We've Seen Over The Years * (9/2003) SADMIND remote command execution on Solaris * <http://archive.cert.uni-stuttgart.de/bugtraq/2003/09/msg00297.html> * “This exploit targets a weakness in the default security settings of the sadmind RPC application. This application is installed and enabled by default on most versions of the Solaris o… text/html 2018-03-24T17:39:02+00:00 Anonymous (anonymous@undisclosed.example.com) http://rockhopper.monmouth.edu/cs/jchung/cs471/cs_471_-_software_management?rev=1521913142 Software Installation & Maintenance ---------- * See the section of General Admin Principles that deals with software and system maintenance. * Software can be evil. * Can open doors to system intrusion through exploitable weaknesses in software, network ports needed by the software. text/html 2018-03-24T19:29:44+00:00 Anonymous (anonymous@undisclosed.example.com) http://rockhopper.monmouth.edu/cs/jchung/cs471/cs_471_-_system_admin_journals?rev=1521919784 Your System Administration Journals * Reasons for administration journaling * See Some General SysAdmin Principles - Documentation. * What goes in the journal? * The code of useful aliases, shell functions or scripts that you've written to manage your systems. * Project task descriptions text/html 2018-03-09T21:02:52+00:00 Anonymous (anonymous@undisclosed.example.com) http://rockhopper.monmouth.edu/cs/jchung/cs471/cs_471_-_virtualization_and_containers?rev=1520629372 Virtualization and Containers ---------- [Hypervisor Virtualization and Containers] Hypervisor Virtualization * Virtualization software on a host computer creates virtual hardware on which an OS file system image is installed and run (a guest OS). * The hypervisor (AKA “virtual machine monitor text/html 2018-03-22T15:30:04+00:00 Anonymous (anonymous@undisclosed.example.com) http://rockhopper.monmouth.edu/cs/jchung/cs471/cs_471_assignments?rev=1521732604 CS 471 Assignments Assignment 4 - Software management, chroot Due: Friday, 3/23/2018, 11:59pm Write your answers in a plain text file or Google doc, and dropbox the text file (or link to a Google doc). Make sure your name appears in what you submit. text/html 2018-04-30T00:48:47+00:00 Anonymous (anonymous@undisclosed.example.com) http://rockhopper.monmouth.edu/cs/jchung/cs471/cs_471_projects?rev=1525049327 CS 471: List of Projects ---------- Project 3 - Configuration Management II Due date: Monday, 4/23/18, 11:59pm Project presentation: Friday, 4/27/18, 2:40pm Using ansible roles and playbooks, complete the following tasks on both your VM and container Linux systems: * basic role: (Add to the basic role that you should already have.) text/html 2018-04-03T17:48:17+00:00 Anonymous (anonymous@undisclosed.example.com) http://rockhopper.monmouth.edu/cs/jchung/cs471/cs_471_reading?rev=1522777697 CS 471 Reading Assignments ---------- Weeks 1-2 UNIX and Linux System Administration Handbook: Chapter 1 Weeks 3-4 UNIX and Linux System Administration Handbook: Chapter 2, 3, 8 Analyzing the Linux boot process. Weeks 5-6 UNIX and Linux System Administration Handbook: Chapter 4 - 8 text/html 2018-04-22T05:04:04+00:00 Anonymous (anonymous@undisclosed.example.com) http://rockhopper.monmouth.edu/cs/jchung/cs471/cs_471_tasks?rev=1524373444 List of Administration Tasks >> Deadline: Thursday, 4/26/18, 11:59pm >> This is a growing list of mandatory system administration/configuration tasks that count toward your Projects grade. >> Each task must be accompanied by a detailed entry in your administration journal (See text/html 2013-01-31T17:57:33+00:00 Anonymous (anonymous@undisclosed.example.com) http://rockhopper.monmouth.edu/cs/jchung/cs471/df_and_units?rev=1359655053 df and Units Run the df command on your Linux machine and observe the output. <poll What units are used in the output of 'df'? (2)> * bytes * kilobytes * megabytes * gigabytes * cylinders * sectors </poll> text/html 2013-04-26T04:45:59+00:00 Anonymous (anonymous@undisclosed.example.com) http://rockhopper.monmouth.edu/cs/jchung/cs471/getting_started_with_glusterfs?rev=1366951559 We will get started on the GlusterFS project by following this online tutorial. Eventually, we want to set up distributed, replicated storage across at least 16 lab machines in HH 310. The instructions at another online tutorial as well as official documentation may help us there. text/html 2011-04-27T18:01:27+00:00 Anonymous (anonymous@undisclosed.example.com) http://rockhopper.monmouth.edu/cs/jchung/cs471/iptables_notes?rev=1303927287 iptables ---------- Overview * Firewall created by the Netfilter (<http://www.netfilter.org>) project * Integrated with the Linux kernel * iptables-specific kernel modules * Stateful packet inspection * The firewall keeps track of each connection passing through it and in certain cases views the contents of data flows in an attempt to anticipate the next action of certain protocols. text/html 2013-01-31T17:57:03+00:00 Anonymous (anonymous@undisclosed.example.com) http://rockhopper.monmouth.edu/cs/jchung/cs471/shell-style_globbing?rev=1359655023 Shell-Style Globbing $ ls "/etc/rc*.d" <poll What does the above expression in double quotes mean? (3)> * “/etc/r” followed by 0 or more “c”, followed by any character, followed by d * Files or directories in the /etc directory that begin with text/html 2018-04-27T18:38:45+00:00 Anonymous (anonymous@undisclosed.example.com) http://rockhopper.monmouth.edu/cs/jchung/cs471/start?rev=1524854325 CS 471 - System Administration Semester: Spring 2018 ---------- Announcements * Link to current syllabus (Updated: 2/9) * Course page on cssegit (gitlab): <https://cssegit.monmouth.edu:2443/jchung/cs471/tree/master> ---------- Content * Introduction, Installation (Updated: 1/18) * Linux installation instructions, Week 1 * Server Management, Week 1 * Monitoring I (Updated: 1/26) * OS, Bootup/Shutdown, Services (Updated: 1/30) text/html 2013-01-31T17:57:56+00:00 Anonymous (anonymous@undisclosed.example.com) http://rockhopper.monmouth.edu/cs/jchung/cs471/what_s_installed?rev=1359655076 What's Installed? <poll Is a gcc (C compiler) package installed in your Linux machine? (2)> * Yes * No </poll>