backups:
# tar -czf /backup/home.tgz /home &
You can use these commands and tools when using the shell or writing shell scripts:
> chsh — Command used to change one's login shell
> kibitz — Allows two-person interaction with a single shell
> mc — A visual shell named the GNU Midnight Commander
> nano — An easy-to-use text editor for the console
> system-config-users — A graphical user-management utility that can be used to change one or more user login shells
> shar — Command used to create shell archives
> vi — The vi (actually vim) text editor
Reference
> http://www.linuxgazette.com/issue70/ghosh.html — A Linux Gazette article on 'Bootstrapping Linux,' which includes much detail on the BIOS and MBR aspects of the boot process.
> http://www.lostcircuits.com/advice/bios2/1.shtml — the LostCircuits BIOS guide; much detail on the meaning of all those BIOS settings.
> http://www.rojakpot.com/default.aspx?location=1 — The BIOS Optimization Guide; details on tweaking those BIOS settings to your heart's content.
> http://www-106.ibm.com/developerworks/linux/library/l-slack.html — A link through IBM's website to an article on booting Slackware Linux, along with a sidebar about the history of System V versus BSD init scripts.
> /usr/src/linux/init/main.c — This file in the Linux source code is the best place to learn about how Linux boots. Fascinating reading, really. Get it from the source!
> http://sunsite.dk/linux-newbie/ — Home page for the Linux Newbie Administrator Guide — a gentle introduction to Linux System Administration.
> http://www.gnu.org/software/grub/manual/ — The still yet-to-be-completed GRUB Manual. On your Fedora system, info grub provides a plethora of information, and a sample grub.conf file (/boot/grub/menu.lst is a symbolic link to /boot/grub/grub.conf; use either name) can be found in /usr/doc/grub.
> LILO User's Guide — Werner Almesberger's definitive technical tome on the LInux LOader, or LILO, and how it works on Intel-based PCs. Look under the /usr/share/doc/lilo*/doc directory for the file User_Guide.ps, which can be viewed with the gv client. LILO has been dropped from Fedora; GRUB is now the default boot loader supported in the distribution.
> 'Managing Initscripts with Red Hat's chkconfig' — by Jimmy Ball, Linux Journal, April 2001; pp. 128-132.
> 'Grub, Glorious Grub' — Hoyt Duff, Linux Format, August 2001; pp. 58-61. A tutorial on the GRUB boot loader.
> http://www.redhat.com/docs/manuals/linux/RHL-9-Manual/custom-guide/s1-services- serviceconf.html — Red Hat's guide to use the system-config-service client (then called redhat-config-service).
> http://www.linuxbase.org/spec/refspecs/LSB_1.0.0/gLSB/sysinit.html — The Linux Standard Base description of system initialization; this is the standard.
CHAPTER 12
System-Monitoring Tools
To keep your system in optimum shape, you need to keep a close eye on it. Such monitoring is imperative in a corporate environment where uptime is vital and any system failures can cost real money. Whether it is checking processes for any errant daemons or keeping a close eye on CPU and memory use, Fedora provides a wealth of utilities designed to give you as little or as much feedback as you want. This chapter looks at some of the basic monitoring tools, along with some tactics designed to keep your system up longer. Some of the monitoring tools cover network connectivity, memory, and hard drive use, but all should find a place in your sysadmin toolkit. Finally, you will learn how to manipulate active system processes, using a mixture of graphical and command-line tools.
Console-Based Monitoring
Those familiar with UNIX system administration already know about the ps or process display command commonly found on most flavors of UNIX. Because Linux is closely related to UNIX, it also benefits from this command and allows you to quickly see the current running processes on the system, as well as who owns them and how resource hungry they are.
Although the Linux kernel has its own distinct architecture and memory management, it also benefits from enhanced use of the /proc file system, the virtual file system found on many UNIX flavors. Through the /proc file system, you can communicate directly with the kernel to get a deep view of what is currently happening. Developers tend to use the /proc file system as a way of getting information out from the kernel and for their programs to manipulate it into more human-readable formats. The /proc file system is beyond the scope of this book, but if you want to get a better idea of what it contains you should head on over to http://en.tldp.org/LDP/Linux-Filesystem-Hierarchy/html/proc.html for an excellent and in-depth guide.
Processes can also be controlled at the command line, which is important because you might sometimes have only a command-line interface. Whenever an application or command is launched, either from the command line or a clicked icon, the process that comes from the kernel is assigned an identification number called a
# system-config-display &
[1] 4286
In this example, the system-config-display client has been launched in the background, and the (bash) shell reported a shell job number ([1] in this case). A job number or job control is a shell-specific feature that allows a different form of process control, such as sending or suspending programs to the background and retrieving background jobs to the foreground (see your shell's man pages for more information if you are not using bash).
The second number displayed (4286 in this example) represents the process ID. You can get a quick list of your processes by using the ps command like this:
# ps
