cant mount cdrom

[cstrasser]

hi .... my cd rom won't mount .. says invalid block device ??
ne1 have an idea on what to do to get it working ... the drive is fine if i boot to windows ....

[red_over_blue]

Try posting the file /etc/fstab and the output from the following command run as root:


dmesg | grep hd


and we'll see what we can do.

If you don't now already.... to cut and paste in linux just highlight the text using the mouse (that's all... just hightlight) and then click both mouse buttons (or the scroll wheel) to paste.

[cstrasser]

ok there i see the problems ... looks like my hdc driver has gone
away ?
worked yesterday ??
ps .. what is dmesg

LABEL=/ / ext3 defaults 1 1
none /dev/pts devpts gid=5,mode=620 0 0
none /proc proc defaults 0 0
none /dev/shm tmpfs defaults 0 0
/dev/hdb3 swap swap defaults 0 0
/dev/cdrom /mnt/cdrom iso9660 noauto,owner,kudzu,ro 0 0
/dev/fd0 /mnt/floppy auto noauto,owner,kudzu 0 0






Kernel command line: ro root=/dev/hdb2
ide0: BM-DMA at 0x9800-0x9807, BIOS settings: hda:DMA, hdb:DMA
ide1: BM-DMA at 0x9808-0x980f, BIOS settings: hdc:pio, hdd:pio
hda: WDC AC34000L, ATA DISK drive
hdb: WDC WD200AB-00CMB0, ATA DISK drive
hdc: CRD-8400B, ATAPI CD/DVD-ROM drive
hda: 7814016 sectors (4001 MB) w/256KiB Cache, CHS=969/128/63, (U)DMA
hdb: 39102336 sectors (20020 MB) w/2048KiB Cache, CHS=2434/255/63, (U)DMA
hda: hda1
hdb: hdb1 hdb2 hdb3
hdc: driver not present
hdc: driver not present
hdc: driver not present
hdc: driver not present

[red_over_blue]

dmesg will show the output you see at boot-time. When you use the "|" character, that passes that text to whatever command comes next, in this case "grep hd". So, the command


dmesg | grep hd


says "display the boot messages, but only lines containing the text hd". Then you will know which device is associated with your hardware. In your case, it looks like hdc is your cdrom drive. Change the entry in /etc/fstab from


/dev/cdrom /mnt/cdrom iso9660 noauto,owner,kudzu,ro 0 0


to


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


and it should work.

[red_over_blue]

If it is also a DVD drive, you can add the following:


mkdir /mnt/dvd


and then add the following line to /etc/fstab


/dev/hdc /mnt/dvd udf user,exec,dev,suid,ro,noauto 1 1


and when you want to mount that drive as DVD (udf), just mount /mnt/dvd. (although you don't need to mount the dvd for mplayer) It is perfectly fine to have more than one entry in fstab for each device. It is specific to the filesystem type.

[snowtion]

here is my /etc/fstab:

/dev/hdc1 / ext3 defaults 1 1
none /dev/pts devpts mode=0620 0 0
/dev/hdc6 /home ext3 defaults 1 2
none /mnt/cdrom supermount dev=/dev/hda,fs=auto,ro,--,iocharset=iso8859-1,codepage=850,umask=0 0 0
none /mnt/floppy supermount dev=/dev/fd0,fs=auto,--,iocharset=iso8859-1,sync,codepage=850,umask=0 0 0
none /proc proc defaults 0 0
/dev/hdc5 swap swap defaults 0 0

i deleted the symbolic link /dev/cdrom, because one website while i was trying to figure it out told me to and now nothing happens when i cd /mnt/cdrom, but when try to do this:

mount /dev/hda /mnt/cdrom (as root)

I get this:

mount: block device /dev/hda is write-protected, mounting read-only
mount: No medium found

so i dont know what is going on, do i just do the same thing that you told cstrasser?

[cstrasser]

ok ......... i tried changing the /etc/fstab ( made sense to me ) but i still get the same error .... re the dmesg thing ... nice :) glad i asked

[snowtion]

I have located the problem and just edited the /etc/fstab like you said. But their is another problem with my cdrom drive. When i put in a software cd, it will run and show me all the files, but when i want to take the disk out, i cant just press the eject button on the cdrom drive. I have to click the eject button when right clicking on the cdrom icon. And then once it does come out, it will suddenly go back in right after it came back out. What is wrong here?

Also when i put in a music cd, i get the error dont have rights and **** like that. Is the reason because i dont have a cd player program on my computer. I am using mandrake 9 btw and only installed the 1st cd.

[cstrasser]

did you unmount the cd rom... if not you can't open the door ...try :
unmount /mnt/cdrom then the eject should work fine

[mdwatts]

Originally posted by cstrasser

ps .. what is dmesg



Anytime you do not know what a command does, see if it has a related manpage.

man dmesg

You may need the 2nd and 3rd cd as they probably contain the multimedia apps (cd player etc.).

[cstrasser]

ok .... got it ............. found another post from somone who had the same problem .... just type depmod -ad and bingo all starts to work fine ...
no idea what it does ( excpt handle dependency descriptions for loadable kernel modules ?? yeah whatever) so between tha /etc/fstab change and the depmod thing i am good to go

[mdwatts]

Are you using Redhat 7.2 or 7.3 as that is a known problem as you need to run depmod -ae to fix.

Always a good idea to include your distro/version whenever posting a question as it sometimes saves time for both of us.