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Lesson 10

File System Configuration Conclusion

The way you configure your filesystem depends on your priorities regarding performance, security, and synchronization. This module explored a number of commands that allow you to optimize and correct errors with your configuration, including mke2fs, tune2fs, dump2fs and debugfs.
You also investigated the advantages and disadvantages of using an automounter. Although automounting allows the on-demand mounting of removable media such as CD-ROMs and floppies, its use opens security holes. However, automounting is highly convenient because filesystems are accessible automatically whenever needed. You determine the configuration of the automounter based on your security needs.
There are two Linux automounters that can be configured and used on the Linux system: amd and autofs. amd is user-level and requires no kernel support. autofs requires kernel support is simpler to administer; however, the autofs RPM has to be installed and local configuration may be required.
Next, you learned how to synchronize filesystems between the local host and a remote machine using the utilities rdist and rsync. For security reasons, using rsync with ssh is preferable.
Then, you learned how to monitor the usage of your system's filesystems with the following commands: df, repquota, du, and the utility Gnome DISKFree. It is important to ensure the information is readily available to your users and enough space has been allocated to store the needed files. Finally, you learned how to troubleshoot common filesystem problems including overflow of the root partition, filesystem corruption caused by an improper shutdown, and disk failure.

Learning objectives

Having completed this module, you should be able to
  1. Use the mke2fs command to adjust the filesystem's block size
  2. Use tune2fs, dumpefs, and debugfs to optimize and configure the ext2 filesystem
  3. Discuss the use of the automounter
  4. Set up the automounter
  5. Use rdist to synchronize files between the local host and a remote machine.
  6. Use rsync to synchronize files between the local host and a remote machine
  7. List the commands for monitoring filesystem usage.
  8. Resolve filesystem problems

Glossary terms
This module introduced you to the following terms.
  1. Automounter: An automounter is a program that automatically mounts filesystems when those filesystems are first accessed.
  2. Automounting: Automounting allows the system to automatically mount filesystems when those filesystems are first accessed.
  3. Automount point: An automount point is a user-specified filesystem under which the automounter mounts a particular filesystem.
  4. Block size: Block size is the number of bytes allocated to individually accessible units in the ext2 filesystem.
  5. Configuration file: A configuration file contains information such as settings or options to be used by a hardware device or program.
  6. CVS: CVS, Concurrent Versions System, is a system that keeps a set of files in sync.
  7. Map file: In automounter parlance, the map file is a configuration file that associates a directory key with a device to mount when that directory key is accessed.
  8. Mount count: The number of mounts previously performed on a filesystem since the last filesystem check.
  9. Packet sniffing: Packet sniffing is an example of spoofing in which a sniffing program is on a segment between two communicating end points. An intruder can then pretend to be one end of the connection to a victim and eavesdrop on data passed between the two end points.
  10. rsh: the remote shell, is a utility that allows users to log in to a remote system. However, it does not use any type of encryption and therefore is insecure.
  11. Spoofing: Using somebody else's IP address to create TCP/IP packets is called spoofing.
  12. ssh: ssh, the secure shell, is a utility that allows log in to a remote system using encrypted data transfer.
  13. Trust: Trust is a basic concept in security. The ability to trust means relying on the availability of another computer and the integrity of information provided by the other computer.
The next module discusses system and kernel logging.

Administering Local Filesystems - Quiz

Before moving on to the next module, click the Quiz link below to check your knowledge of administering local filesystems.
Administering Local Filesystems - Quiz