LPI Linux Certification in a Nutshell, 2nd Edition

Hardware (Topic 2.204)

Review Questions

1. You have just updated the /etc/raidtab file. What command should you run to create the RAID array?

2. What file can you read to determine which USB devices have been recognized on your system?

3. What three things can you do with the modprobe command?

4. You have just added a new device but do not know the interrupt that this device is using. What file in the /proc directory can you query?

5. A coworker has just added a new CD/DVD-RW drive via USB. You wish to verify its speed. What command allows you to do this?

Answers

1. mkraid.

2. /proc/bus/usb/devices.

3. You can add modules, delete modules, and list the modules that can be run on the system.

4. /proc/interrupts.

5. syctl -a.

Exercises

1. View the /proc/interrupts file and compare it to the output of the lspci -vv command. Notice that you can get the same IRQ information from both. However, the lspci -vv command gives you much more information about the devices themselves, as long as they are PCI based.

2. Use the hdparm command to read the parameters on your devices. For example, if you have an IDE drive as your first disk, issue the following command as root:

   hdparm /dev/hda

   Review the output. Is DMA turned on or off? Be careful when enabling or disabling any settings. Enable features using hdparm only if you are sure your hard disk supports them. Similarly, disabling features might severely impact disk performance. If you wish, use the sysctl command to discover the speed of your CD-ROM. Then use hdparm's -E option to specify ...