Unable to mount root on 1.2.0 CD

Matthew Dillon dillon at apollo.backplane.com
Mon Apr 11 22:54:30 PDT 2005

:The system boots the LiveCD but then drops me to a mountroot
:prompt. I have a LITE-ON LTR-24102B cd rw drive.
:The dmesg lists it twice:
:acd0: CD-RW <LITE-ON LTR-24102B> at ata1-slave PIO4
:cd0: <LITE-ON LTR-24102B 5S0F> Removable CD-ROM SCSI-0
:Then it tries a bunch of root mounts using cd9660:foo,
:where foo is several different combinations of cd device
:identifiers. All of them fail.
:Then I try the same thing with all of the cd devices in the
:/dev directory on the cd. Nada.
:Anyway, I'd like to send the whole dmesg, but I don't see a
:way of getting it from my console into an email.

    Hmm.  Well, up until the kernel boots the loader is using BIOS calls
    to access the CD.  Those obviously work.  But if the kernel itself is
    not able to access the CD it could be a driver problem.

    Try doing a boot -v (drop into the boot prompt using menu option 6 and
    type 'boot -v'), and see if you can pick the ATA device lines.  See
    what it identifies the ATA device as and try to find a PCI ID in the
    identification line or earlier on that has the same PCI bus identifier.

    If you have a second computer and can attach a serial port to the
    one that isn't booting right, you can boot it over the serial port and
    record the sequence on the second computer.  It's a 9600 8N1 connection.
    The boot loader will output to both the console and the serial port but
    to make the kernel output to the serial port you have to give it the -h
    option, e.g. drop into the boot prompt via the serial link and type
    'boot -h -v'.

    There may not be anything we can do.  If the machine has a USB port
    it might be capable of booting from a USB disk key, but without a
    working ATA device there isn't much you could do with it beyond that.

					Matthew Dillon 
					<dillon at xxxxxxxxxxxxx>

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