Convert to PalmDoc by Yao Feng 关于作者: He is a Linux fan besides working in a campus network center. Hobbies:hamradio, swimming. Using Linux as a normal user for one year, doing system administration on Linux/Unix for another year. Finishing the graduate thesis on billing systems with a Linux based proxy server. 正文: Find out what the name of your CD-ROM device is Mount (make available) your CD-ROM Accessing your CD-ROM Unmounting your CD-ROM Mounting and unmounting without being root Troubleshooting Talkback form for this article

How to use your CD-ROM under Linux

摘要:

This article gives a short but useful description on how to use your CD-ROM under Linux. It describes how to find the CD-ROM device, mount (make available) the CD-ROM, read the contents, umount it and gives some hints for troubleshooting.

Find out what the name of your CD-ROM device is

The 'hdc: CD-ROM CDU701, ATAPI CDROM drive' line tells us that you have a CD-ROM IDE/ATAPI-CD drive attached on the computer. Linux assign it a device name-'hdc' for access later on. The name of device depends on the hardware type and it is hdc in the first case and sdc in the case where you have SCSI CD-ROM.  

Mount (make available) your CD-ROM

The device name of the CD-ROM is the one that was shown in the output of the dmesg command.
 

Accessing your CD-ROM

Filesystem         1024-blocks
Used Available Capacity Mounted on
/dev/sda1    2974519   1516768    1303931   54%   /
/dev/sda3    2686158   2378788    153548    94%   /home
 /dev/hdc     603646     603646       0     100%  /cdrom

Now you can now access your cd-rom like a normal directory at /cdrom.  

Unmounting your CD-ROM

Mounting and unmounting without being root

When you are logged in as root you can do anything but you can also accidently do more than you wanted to. It is therefore better to make the cdrom mountable for ordinary users. To give the privileges to mount a drive to any user you must first log in as root and do 3 things:

1. make the directory /cdrom world writable
2. make the device world writable
3. edit the fstab

To make the directory /cdrom world writable you type (while no cdrom is mounted!):

#chmod 777 /cdrom

To make the device world writable you type (use the device name as described in the first chapter):

for the ATAPI cdrom: #chmod 666 /dev/hdc

for the SCSI cdrom: #chmod 666 /dev/scd0

Now you must edit /etc/fstab and give the permission to mount the cdrom to any user. This is done by inserting the line following line:

/dev/hdc /cdrom iso9660 ro,noauto,user 0 0

In the case of the scsi cdrom this looks like: /dev/sdc0 /cdrom iso9660 ro,noauto,user 0 0

Please note that there might already be a line for the /dev/hdc device (or /dev/sdc0) in this case you have to edit the line and not add a new entry. The line tells Linux on which directory to mount the cdrom and with device to use. It tells Linux also that the file system is iso9660, that it should be mounted read only and that it should never be mounted at startup (when there might not be a CD in the drive). The option "user" means that any user can mount the drive.

Save the fstab file and log in as normal user. Now insert a CD into the drive and mount it with the command:

$mount    /cdrom

Easy, isn't it?
It is now possible to use this short form because Linux can get all the other parameters from /etc/fstab.

Troubleshooting

• Failed umount CD-ROM and got 'device is busy' message. (here we had mounted CD-ROM previously at /cdrom )

• For easy access later

• When typing umount /cdrom you get the message umount: /cdrom is not in the fstab (and you are not root)

• Listen to Audio-CDs

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2001-01-01, generated by lfparser version 2.4