Linux System Administration
Tom Adelstein, Bill Lubanovic
Language: English
Pages: 300
ISBN: 0596009526
Format: PDF / Kindle (mobi) / ePub
Linux is now a standard corporate platform with users numbering in the hundreds of millions, and there is a definite shortage of talented administrators. Linux System Administration is ideal as an introduction to Linux for Unix veterans, Mcses, and mainframe administrators, and as an advanced (and refresher) guide for existing Linux administrators who will want to jump into the middle of the book. Inside, you'll learn how to:
- Set up a stand-alone Linux server
- Install, configure, maintain, and troubleshoot a Dns server using Bind
- Build an Internet server to manage sites, perform email and file transfers, and more
- Set up an email service for a small-to-medium-sized site, complete with authentication
- Install and configure Apache, Php, and MySql on a web server built from scratch
- Combine computers into a load-balanced Apache web server cluster based on the free Linux Virtual Server
- Set up local network services from distributed file systems to Dhcp services, gateway services, print services, user management and more
- Use Linux virtualization with Xen or Vmware to run multiple kernels on one piece of hardware; manage each kernel's access to processor time, devices, and memory
- Create shell scripts and adapt them for your own ne
setup, 22–32 installing, 74 Spam Assassin, 36 procedures on compilation failure, 80 testing, 110 requirements, 74 mail transport agents (see MTAs) server and users, setting up, 83 mail user agents (MUAs), 103 services configured using, 74 maildir format, 119 special daemons, 76 maildir versus libc clients, 11 user management, 91 masquerading, 174 web site setup, 83 MaxClients directive, Apache, 134 MaxRequestsPerChild directive, K Apache, 134 mbox storage format, 119 K3b, 246
domain list in used in Postfix In Figure 2-7, you will notice that two commas follow the name localhost.centralsoft. org. Remove the second comma. In Figure 2-8, the Postfix configurator inquires about synchronous updating. We will cover administering mail servers in greater detail in Chapter 5; for now, answer
id: 43756 ;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 1, ADDITIONAL: 0 ;; QUESTION SECTION: ;centralsoft.org. IN A ;; ANSWER SECTION: centralsoft.org. 86400 IN A 70.253.158.42 ;; AUTHORITY SECTION: centralsoft.org. 29437 IN NS server1.centralsoft.org. Received 71 bytes from 68.94.156.1#53 in 30 ms This information came from the IP address 68.94.156.1, port number 53, which is the nameserver specified in the resolv.conf file of the desktop performing the lookup. You can use host
programmers would have rushed in and started typing (some without having read the data format or requirements). Readers of this book are more disci- plined, though, as well as better looking. They’ve had to fix the messes that the other programmers have made and don’t want to make the same mistakes themselves. Data Format: The /etc/passwd File The password file usually contains standard system accounts such as the mighty root, application accounts such as apache, and user accounts. Here are
uid numbers: #!/bin/bash pattern=$1 IFS=":" while read account password uid gid name directory shell do # Exact matches only! if [[ $uid -gt 500 && $(echo $name | egrep -i -c "$pattern") -gt 0 ]]; then echo "$account:$password:$uid:$gid:$name:$directory:$shell" fi done < /etc/passwd Scripting Language Shootout | 229 If you run a shell script with a -v or -x option, bash will print each command before executing it. This can help you see what the script is actually doing. The Perl