Answers to Assessment Test

1. C. mkfs is a tool for creating a new filesystem, which is something you're likely to need to do in an emergency recovery situation. fdformat does a low-level format on a floppy disk, WordPerfect is a word processor, and traceroute helps diagnose network connectivity problems. You're unlikely to need to use any of these tools from an emergency disk. See Chapter 9 for more information.

2. D. Swap space is being used lightly, and so it isn't degrading system performance. The available swap space is large enough that an unexpected spike in memory usage probably won't overwhelm it. The swap space should not be eliminated in case such a spike arrives, though. Adding RAM might improve performance somewhat, but most likely, such an action won't improve it substantially. The swapon command won't improve performance, but it could be used to add more swap space if memory demands increased. See Chapter 8 for more information.

3. A, B, D. /etc/modules.conf includes parameters to specify all of the indicated information, but the Linux kernel never automatically recompiles a kernel module; that's a task for you as an administrator. See Chapter 6 for more information.

4. A, D. The Advanced Configuration Power Interface (ACPI) and Advanced Power Management (APM) are power management protocols. The Point-to-Point Protocol (PPP) forms TCP/IP network links over serial or telephone lines, and the Simple Mail Transfer Protocol (SMTP) handles e-mail exchanges. See Chapter 8 for more information.

5. A. When shutting down certain servers, telinit first tries asking them to shut themselves down by sending a SIGTERM signal. The server can then close open files and perform other necessary shutdown housekeeping. If the servers don't respond to this signal, telinit becomes more forceful, and passes a SIGKILL signal, which is more likely to work but doesn't give the server a chance to shut itself down in an orderly fashion. See Chapter 6 for more information.

6. B, D. You're unlikely to need to use a Telnet client on a firewall, but an intruder who breaks into the firewall could use it to access your internal systems. A firewall shouldn't run any servers that aren't absolutely required, and an Apache server is almost certainly not required. init is the master process on a Linux system, and cannot be removed without damaging the system. Likewise, the Linux kernel controls everything else; without it, the computer isn't a Linux computer at all. See Chapter 4 for more information.

7. B. Tracking down and removing or changing the permissions of a former user's files can prevent confusion or possibly even spurious accusations of wrongdoing in the future. Unless the user was involved in system cracking, there's no reason to think that the user's password will be duplicated in the password database. No system file's ownership or permissions should need changing when deleting a user. Although overwriting deleted files with random data may be useful in some high-security environments or with unusually sensitive data, it's not a necessary practice on most systems. See Chapter 4 for more information.

8. B. In 2001, all major Debian-based distributions use not just the Debian package system but many Debian component packages as a starting base. Debian is available for non-x86 CPUs, so Pentium optimization is not universal (although Corel Linux does use a Pentium-optimized kernel). RPM is available on Debian and its derivatives, and it can be used, although it's generally not recommended. The Debian package format is the second most popular in the Linux world, behind RPM but ahead of tarballs—at least as a basis for distributions. See Chapter 3 for more information.

9. C. The second set of permission bits (rw-) indicates that the file's group (audio) may read from and write to the file. This permission string ensures that, if sound has more than one member, multiple users may access the file. The leading c indicates that the file is a character device file, not a directory. chmod 660 loud will not change the file's permissions; 660 is equivalent to rw-rw----. See Chapter 4 for more information.

10. A. tcpd is the TCP Wrappers program. This program provides some security features that are largely provided directly by xinetd, so most systems that use xinetd don't call tcpd from xinetd. The other options appear in both types of files, although arguments for the server aren't required for either super server. See Chapter 6 for more information.

11. D. You can easily edit that line to change the program run by the $CC variable, or you can assign different values to the variable within a conditional in support of different system configurations. Specifying the program directly will as easily ensure that it's run. Any program that can be called from a variable can be called directly. Variable assignment doesn't allow the script to call programs for which the user lacks execute permission. See Chapter 6 for more information.

12. B. Kernel bugs often manifest themselves in the form of kernel oopses, in which an error message including the word oops appears on the console and in log files. Although a program might conceivably trigger a kernel oops, the bug is fundamentally in the kernel. (Kernel oopses also often indicate hardware problems.) See Chapter 9 for more information.

13. A, D. The biggest problem with resizers is the potential for data loss in the event of a crash or power failure during the resize operation. They also can render a system unbootable because of a moved kernel. This latter problem can be overcome by reinstalling LILO. Linux doesn't use partition ID codes except during installation, and resizing programs don't touch these codes. PartitionMagic and resize2fs are two programs commonly used to resize ext2 filesystems. See Chapter 7 for more information.

14. D. XFree86 4.0.x includes a new driver architecture, so some of 3.3.6's accelerated drivers haven't been ported to the new system as of version 4.0.3. In such cases, using the old server can provide a snappier display. It's 4.0.x that provides support for multiple monitors. The presence of a separate accelerated driver in 3.3.6 does not necessarily mean that the 4.0.x support is slower. See Chapter 2 for more information.

15. B. iptables is the tool for configuring the 2.4.x Linux kernel's firewall features. (ipfwadm and ipchains perform these tasks for the 2.0.x and 2.2.x kernels, respectively.) Apache is a Web server and wall sends messages to all currently logged-on users. TCP Wrappers controls access to specific servers but it isn't a firewall per se. See Chapter 1 for more information.

16. D. setserial returns information on the RS-232 serial port's hardware and current operating status, such as the port speed. See Chapter 9 for more information.

17. B. These scripts hold startup commands individualized for their host ("local") computer, as opposed to provided with the distribution. In principle, these scripts could be used for any of the other listed purposes, but this isn't their usual function. See Chapter 6 for more information.

18. A. The SCSI Configured Automatically (SCAM) protocol, if supported by the host adapter and SCSI devices connected to it, auto-configures those devices. The Server Message Block (SMB) is a protocol used in Windows file sharing and implemented by Samba in Linux. The Advanced SCSI Programming Interface (ASPI) is a method common in DOS and Windows for programs to interface with SCSI devices. The Advanced Technology Attachment Packet Interface (ATAPI) is a protocol used by many EIDE devices. See Chapter 1 for more information.

19. A. Testing your emergency tools can save you time when the pressure is on during a restore. In extreme cases, testing tools and finding problems with them may allow you to correct problems that might cause hours of effort in an emergency. Distributions' emergency disks may or may not contain the exact tools you need to restore a system. They're unlikely to contain commercial backup tools. Recovering by doing a slim Linux installation and then using that to recover a backed-up system is one approach to the problem of doing a complete restore, but it's not the only solution. Assuming you've made a complete backup to CD-R, it's possible to completely restore a system from CD-R. See Chapter 7 for more information.

20. C. Ipd is a multifunction tool that accepts print jobs from local and remote systems, maintains print queues, and sends data to printers (both local and remote). It does not, however, feed back information on a printer to applications. See Chapter 8 for more information.

21. C. Option A extracts files from the archive without displaying their names. Option B lists the files in the archive; but without the -verbose (v) option, it doesn't list file sizes or time stamps. Option D will cause tar to attempt to extract the named file from its standard tape device. See Chapter 3 for more information.

22. C. Switches allow full-duplex operation and reduce the chance of collisions on a network relative to hubs. Both devices come in 100Mbps models and models supporting both fewer than and greater than 5 devices. Neither type of device normally supports 10-Base5 cabling; they're both intended for use with twisted-pair network cables. See Chapter 5 for more information.

23. C. In Linux, killall kills all processes of the specified name. When the superuser issues the command, it will kill processes owned by normal users, as well as root's processes of the specified name. It can take a signal name or number as a parameter, but if that's omitted, it defaults to a TERM signal. The advantage of killall over kill is that you don't need to look up a PID to use killall. There is no -n parameter for killall. See Chapter 7 for more information.

24. B. Some distributions use particular boot floppies (or other boot media) for specific installation media. Others allow you to select the installation medium from a list early in the installation process. None require you to enter this information at the lilo: prompt. Most distributions support multiple installation media. The installer cannot auto-detect your installation medium, except insofar as an installer can be written to support just one, with different boot floppies for different media. See Chapter 2 for more information.

25. A, B, D. The USB port has been used for connecting just about every type of external peripheral, including keyboards, mice, modems, printers, scanners, cameras, and removable-media drives. USB is inadequate for driving a monitor, but some monitors include USB hubs or USB speakers. RAM is always installed internally, never via an external port like USB. See Chapter 1 for more information.

26. D. A login problem isolated to one user is almost certainly related to something in the user's configuration files. One possible source of the problem is the file or directory controlling the window manager or desktop environment. IceWM isn't the default window manager for KDE, so .icewm isn't the appropriate directory to delete; .kde is. See Chapter 2 for more information.

27. B. The output redirection operator is >, so option B sends the output of uptime to uptime-stats.txt. The echo command displays information on the screen, so option A simply causes uptime uptime-stats.txt to appear. Option C uses a pipe. If uptime-stats.txt were a program, it would process the output of uptime, but the result of this command will probably be a file not found or permission denied error. Option D uses an input redirection operator, so uptime receives the contents of uptime-stats.txt as its input. See Chapter 9 for more information.

28. A. System cron jobs are controlled through /etc/crontab, which normally specifies several directories whose contents are run at varying intervals, so copying a script to one of these directories turns it into a system cron job. The crontab program is used to create user cron jobs. Both options B and C might work, if the computer has a user called system, which isn't a standard account name. Cron jobs created in this way would work with the system user's privileges, but they wouldn't be system cron jobs in the sense discussed in Chapter 7. See Chapter 7 for more information.

29. B. Most Unix applications can be recompiled on Linux to function, and Windows includes support for DOS programs. Linux and Windows NT/2000 are both well suited to use on networks. Linux, not Windows, is the OS that's best suited to configuration via text-based tools. Windows, not Linux, supports the most popular office productivity applications, such as Microsoft Office. See Chapter 1 for more information.

30. B. A firewall is normally a first line of defense, either on the network as a whole or on an individual computer. If the firewall doesn't block access (because of a bug, misconfiguration, or other problem), subsequent controls may do the job. Server options are one such subsequent control. See Chapter 5 for more information.

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