Originally Published: Wednesday, 8 December 1999 Author: Craig Bamford
Published to: enhance_articles_hardware/Hardware Articles Page: 1/1 - [Printable]

Utilizing Two CD-Roms with Linux

Have you ever tried anything new? Have you ever decided to go against the flow? Well, I have done just that in deciding to convert from Windows to Linux. The only problem with that is the fact that Linux detects and assigns its hardware differently from Microsoft Windows(r).

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Have you ever tried anything new? Have you ever decided to go against the flow? Well, I have done just that in deciding to convert from Windows to Linux. The only problem with that is the fact that Linux detects and assigns its hardware differently from Microsoft Windows(r). My system has in it a Pioneer(r) 40x CD-ROM drive and a Hewlett Packard(r) CD-Writer Plus 7200i.

After installing Linux Mandrake 6.1, I discovered that I could only access the HP CD-ROM and not the Pioneer 40x, mainly because the HP was the master device on the secondary IDE controller. Looking at the /etc/fstab file, it showed only the HP designated as "cdrom". It is mounted from the /dev/cdrom file. Once mounted it was accessible from the /mount/ directory. The problem was: how was I going to access the 40x CD-ROM? This was done through a process of discovering what designation that Linux assigned to the CD-ROM. Once that was determined, I had to add it to the /etc/fstab file and create a directory from which to view the mounted drive. The final step in this process was to mount the drive and see if it worked.

The main problem with the CD-ROM was to discover its designation. I tried several different methods. First, I looked at the c* files in the /dev/ directory. I could find no file other than the "cdrom" file that would point to the 40x CD-Rom drive. Next I checked the rest of the files in the /dev/ directory, looking for something similar, especially considering the different designations given the two hard-drives in my system, hda1, hdb1, and hdb2. There was nothing there to tell me what the designation of the 40x CD-ROM would be. Finally, I watched the boot-up cycle very carefully. I saw the recognition of the hard-drives, the HP CD-ROM as "cdrom" and then I saw my objective. I saw it recognize the Pioneer(r) 40x CD-ROM as "hdd". Thus I had accomplished the first part of my project.

The next step in mounting my second CD-ROM drive was to add it to the /etc/fstab file. I found that when I tried to mount the CD-ROM drive, I received an error stating that the particular device was not in the "fstab" file, so I went to the /etc/ directory and edited the "fstab" file. Once in the file I saw the following information about the HP(r) CD-ROM and just mimicked that data to make the 40x CD-ROM mountable.

/dev/cdrom /mnt/cdrom auto user,noauto,nosuid,exec,nodev,ro 0 0

After seeing this, I input the following line:

/dev/hdd /mnt/cdrom1 auto user,noauto,nosuid,exec,nodev,ro 0 0

That was the conclusion of the second part of my project.

The third step in this process was quite easy. This was to add a directory in the /mnt/ directory to allow me to access the mounted drive, which had to coincide with the directory that I put into the "fstab" file as seen above. That directory was "cdrom1", since there was already a "cdrom" directory. So, I went back to the root directory then, into the /mnt/ directory and typed "md cdrom1" and that was all. That was the end of the third part of this project.

Finally, there came the moment of truth. This was to mount the drive, with a CD in it, and see if my work had paid off. To do this, I typed "mount /dev/hdd" and waited for the prompt to return. Seeing no error on the screen I assumed that it had worked, but I had to prove it. Therefore, since I was already in the /mnt/ directory I went to the /mnt/cdrom1/ directory and viewed the directory structure, which matched the CD that I had put in the CD-ROM. It had worked.

Unfortunately, I cannot claim all credit for this success. I was aided by Stephen Morrow during this process, but only as an instructor judging my work and progress and helping me on any missteps I made. This process took quite some time to figure out, but in the end I did it. To recap, after determining the designation of the second CD-ROM device, I added it to the /etc/fstab file so that I could mount the drive. After adding it to the /etc/fstab file I had to add a sub-directory into the /mnt/ directory that coincided with the one I placed in the "fstab" file. Having done that I needed to mount the drive and determine if the changes I made worked. So, I mounted the drive and determined that it had worked. This problem took a while to fix, but it wasn't too difficult. This sort of error would probably have occurred on any computer with two CD-ROMs, but if it occurred with an advanced user or developer, they probably would have caught it and fixed it earlier. However, a newbie user would probably have trouble with this sort of difficulty. Otherwise, it was something rather trivial in the scheme of things and would not prevent me from continuing to use Linux. The only way that this could have been prevented or improved would be from a programming aspect of Linux itself by changing the designation of a second CD-ROM to a more obvious designation, such as "cdrom1", "cdrom-1", "cdroma" or "cdrom-a" so that users could deduce it sooner.

That was my first experience with hardware problems in Linux and I was able to solve it. If you have any experiences as a newbie Linux user with hardware problems please contact me, Craig Bamford, at conan@linux.com. I would be glad to hear about them as well as learn from them.

Hewlett Packard, Pioneer, and Microsoft are all copyright (c) 1999 by the respective companies. Microsoft Windows is (c) 1999, Microsoft Corp.





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