Re: Can't mount DVD any more

[Tong <mlist4suntong@yahoo.com>]

Thanks Justin.

On Thu, 28 Oct 2004 11:27:22 -0600, Justin Guerin wrote:

> On Wednesday 27 October 2004 19:03, Tong wrote:
>> Hi,
>>
>> I used to be able to mount my dvd, but not now any more.
>>
> What did you change in between the times when you could mount it and when 
> you couldn't?  Every detail you can remember is important.

That was long time ago, I don't remember I've done anything
significant to system setting, except from apt update from time to time,
I think the only thing I did was to load more kernel modules for "cdrecord
-scanbus" to report correctly. I now think the reason might be that
my kernel modules mess up with each other.
 
>> Here is my fstab:
>>
>> $ grep dvd /etc/fstab
>> /dev/dvd                /mnt/dvd                auto   noauto,user
>>
> Can you post the full listing of the device node?

Hmm, I don't quite understand what you are asking for. But here are all
the information that I think is relevant:

$ cdrecord -scanbus
scsibus0:
        0,0,0     0) 'SONY    ' 'CD-RW  CRX195E1 ' 'ZYS5' Removable CD-ROM
        0,1,0     1) 'Toshiba ' 'DVD-ROM SD-M1712' '1808' Removable CD-ROM

$ ls -l /dev/dvd
lrwxrwxrwx  1 root root 8 Oct 4 17:18 /dev/dvd -> /dev/hdd

$ grep -Ei 'dvd|hdd' /var/log/dmesg 
Kernel command line: root=/dev/hda8 ro hdc=scsi hdd=scsi max_scsi_luns=1
ide_setup: hdd=scsi
    ide1: BM-DMA at 0xff08-0xff0f, BIOS settings: hdc:DMA, hdd:DMA
hdc: SONY CD-RW CRX195E1, ATAPI CD/DVD-ROM drive
hdd: Toshiba DVD-ROM DSM-1712, ATAPI CD/DVD-ROM drive
ide-cd: passing drive hdd to ide-scsi emulation.

>> When I mount explicitly, I get:
>>
>> % mount -t iso9660 /dev/dvd /mnt/dvd/ mount: wrong fs type, bad option,
>> bad superblock on /dev/dvd,
>>        or too many mounted file systems
>>        (could this be the IDE device where you in fact use ide-scsi so
>>        that sr0 or sda or so is needed?)
>>
>> % mount -t iso9660 /dev/sr0 /mnt/dvd/ mount: block device /dev/sr0 is
>> write-protected, mounting read-only mount: No medium found
>>
>> What I can do?
>>
> Hmm, why did you use /dev/sr0?  Is /dev/dvd a link pointing to it?  If
> it is, then please post the full listing of /dev/sr0.  If it's not,
> indicate why you think /dev/sr0 is the proper device node.

I tried sr0 because of the error message given by mount. 

$ ls -l /dev/sr?
lrwxrwxrwx  1 root root 4 Aug  8 11:48 /dev/sr0 -> scd0
lrwxrwxrwx  1 root root 4 Aug  8 11:48 /dev/sr1 -> scd1
[...]
lrwxrwxrwx  1 root root 4 Aug  8 11:48 /dev/sr9 -> scd9

Oh, I have new discovery now. Since my cdrom is working fine, I looked at
how it is setup.

$ ls -l /dev/cdrom
lrwxrwxrwx  1 root root 8 Aug 18 12:17 /dev/cdrom -> /dev/sr0

Hmm, yes, it was previously linked to /dev/hdc. I changed it from the hint
of the error message given by mount. 

It means /dev/sr1 should be my dvd? 

$ mount -t iso9660 /dev/sr1 /mnt/dvd/ 
mount: block device /dev/sr1 is write-protected, mounting read-only
mount: No medium found

No...

> The error "No medium found" means mount thinks the drive is correct, but
> there's no readable disk in it.  What disk are you trying to mount?
> Don't try to mount a music CD.  Make sure whatever disk you're using is
> valid, or else you'll never get this error to disappear.  Do you have a
> known good data disk you can try?

I'm just trying with the same movie dvd that I tried last time. I remember
that I was able to view the dvd movie before. Now I can't. That why I was
trying to mount it and look into the problem. 

>> Here is my kernel modules:
>>
>> $ lsmod | grep -Ei 'scsi|cd|dvd|ide'
>> ide-scsi                8464   0  (autoclean) scsi_mod 85312   4
>> (autoclean) [sr_mod sg sd_mod ide-scsi] ide-cd
>>   27936   0
>> cdrom                  25056   0  [sr_mod ide-cd] ide-detect
>>    288   0  (autoclean) (unused) ide-disk               12512  12
>> (autoclean) ide-core               94108  12  (autoclean) [ide-scsi
>> ide-cd ide-detect sis5513 ide-disk]
>>
>> Thanks
>>
>> tong
> 
> Oh, yeah, what kernel are you running? 

$ uname -a
Linux cxmr 2.4.25-1-386 #2 Wed Apr 14 19:38:08 EST 2004 i686 GNU/Linux

> Are you running devfs, or udev?

I don't know, but I don't think so.

$ lsmod | grep dev

nothing found.

What should be the standard place to access DVD in my current
situation? -- ide-scsi module doesn't like /dev/dvd, but the /dev/sr{0,1}
that it suggests do not work.

Thanks.

tong