why can't I find /dev/cdrom

mathewzhao · 07-12-2006, 10:14 AM

I want to use my CDROM driver by the following command:
mkdir /mnt/cdrom
mount /dev/cdrom /mnt/cdrom
However,it doesn't work.
At last,I found /dev directory doesn't exist cdrom file at all.
So,could anyone tell me how to find cdrom under /dev? (I guess it changes a new name )

Have a nice day

marozsas · 07-12-2006, 10:25 AM

/dev/cdrom is a link to the real device, e.g. /dev/hdx.
In my system it is the master device on the second IDE controller.

Code:

[root@gold ~]# ls -l /dev/cdrom
lrwxrwxrwx 1 root root 3 Jul 12 04:55 /dev/cdrom -> hdc
[root@gold ~]#

You need to found yours. The best way is look the files named /proc/ide/*/model.
Mine is

Code:

[root@gold ~]# cat /proc/ide/hdc/model
TSST CD-RW/DVD-ROM TSH492B
[root@gold ~]#

so my cdrom is hdc as I told you.

After you know what device is your cdrom, create the proper link with the command:

Code:

cd /dev
ln -s hdx cdrom
ln -s hdx cdrw
ln -s hdx dvd

of course, you don't need links to cdrw and dvd. It is just a hint.

hussar · 07-12-2006, 10:29 AM

/dev/cdrom is usually a link to /dev/hdb, /dev/hdc or /dev/hdd depending on which interface your drive is mounted on. Use the command `dmesg | grep ATAPI` to show you the drives and their devices, then make a link from the device file to /dev/cdrom using the utility ln (take a look at `man ln`). Once you have /dev/cdrom linked to /dev/hd* then you can mount /dev/cdrom on /mnt/cdrom.

Waggs · 07-12-2006, 12:51 PM

Is the drcom listed in /etc/Fstab/? The only time I've had issues with the mount /dev/xyz was when the device was not lited in /Fstab/...

hussar · 07-12-2006, 01:29 PM

It wouldn't necessarily need to be in his /etc/fstab. He can mount it using something like ` mount -t iso9660 /dev/hdx /mnt/cdrom` or `mount -t iso9660 /dev/cdrom /mnt/cdrom`. But you are right in implying that once he has the link set up between /dev/hdx and /dev/cdrom, he could put a line in his /etc/fstab something like this:

/dev/cdrom /mnt/cdrom iso9660 noauto,users,ro,exec 0 0

manishsingh4u · 07-12-2006, 02:07 PM

Please post the output of these 2 commands

Code:

dmesg | grep CD

Code:

dmesg | grep ide

J.W. · 07-12-2006, 07:04 PM

Also, you can only mount a CD when it contains a data disk. Trying to mount an empty drive, or an audio CD will fail. There's nothing to mount if it's empty, and audio CD's lack a valid filesystem. In other words, the difference between Windows and Linux in this regard is that Windows will always show the "D:\" drive (regardless of whether there's anything in it) but Linux will show it only when it contains a data CD and it has been mounted.

Hondro · 07-13-2006, 08:14 AM

The output of commands: "dmesg | grep CD" and "dmesg | grep ide"

Quote:

# dmesg | grep CD:
hdd: TEAC DW-548D, ATAPI CD/DVD-ROM drive
hdd: ATAPI 48X DVD-ROM CD-R/RW drive, 2048kB Cache, UDMA(33)
Uniform CD-ROM driver Revision: 3.12

Quote:

# dmesg | grep ide:
BIOS-provided physical RAM map:
ide: Assuming 33MHz system bus speed for PIO modes; override with idebus=xx
ide0: BM-DMA at 0x4000-0x4007, BIOS settings: hda

io, hdb

io
ide1: BM-DMA at 0x4008-0x400f, BIOS settings: hdc

io, hdd

io
ide0 at 0x1f0-0x1f7,0x3f6 on irq 14
ide1 at 0x170-0x177,0x376 on irq 15
hda: attached ide-disk driver.
hdd: attached ide-cdrom driver.
EXT3 FS 2.4-0.9.19, 19 August 2002 on ide0(3,1), internal journal
EXT3 FS 2.4-0.9.19, 19 August 2002 on ide0(3,6), internal journal
EXT3 FS 2.4-0.9.19, 19 August 2002 on ide0(3,5), internal journal

manishsingh4u · 07-13-2006, 08:53 AM

Quote:

The names of orginal poster and the poster of "output the 2 commands" are different??

Alright, then the device file for your CDROM is /dev/hdd
1) Make a directory /mnt/cdrom

Code:

mkdir /mnt/cdrom

2) Your /etc/fstab must have this line

Code:

/dev/hdd   /mnt/cdrom   auto   ro,noauto,user,exec  0 0

In place of auto, we can use iso9660 also, but auto is recommended.
3) Insett any CD with some data (necessary) in the CD drive and run this command

Code:

mount -a

4) If you don't get any errors, then u r done. See if can access the files on CD

Code:

ls /mnt/cdrom

contiguous · 07-13-2006, 09:00 AM

The default mount folder is mentioned in the man page of 'mount'. Try to review it there.

mathewzhao · 07-13-2006, 09:19 AM

Thank you!
My cdrom doesn't list in /etc/fstab/,and I had found my cdrom is /dev/hdc.

However,when I type the following command,
mount /dev/hdc /mnt/cdrom
(or: mount -t iso9660 /dev/hdc /mnt/cdrom)

I get error messages:
hdc:driver not present
hdc:driver not present
mount:Mounting /dev/hdc on /mnt/cdrom failed:No such file or address

Could anyone exlpain the error messages?

jstephens84 · 07-13-2006, 09:57 AM

try adding this to your fstab
/dev/cdrom /mnt/cdrom auto ro,noauto,owner,user 0 0 :wq

mathewzhao · 07-13-2006, 10:42 AM

I had added the following line to /etc/fstab and reboot
/dev/hdc /mnt/cdrom auto ro,noauto,user,exec 0 0
,but nothing happen!

jstephens84 · 07-13-2006, 11:16 AM

try changing /dev/hdd to /dev/cdrom

Waggs · 07-14-2006, 08:48 AM

So after editing your /etc/fstab, you rebooted and attempted to *mount /cdrom, and nothing happened? Or were you expecting it to auto mount on reboot?