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    SubjectRe: root=/dev/sda1 fails but root=0x0801 works...
    John Z. Bohach wrote:
    > This is probably a question with an obvious answer, but I haven't found it
    > elsewhere, so I hope its okay if I ask here...
    > As the subject says, if I have my kernel command line with
    > '...root=/dev/sda1...' then I get
    > VFS: Cannot open root device "sda1" or unknown-block(0,0)
    > however, everything else being the same, if I have
    > '...root=0x0801...', then it works fine. Note that
    > SCSI device sda: 2001888 512-byte hdwr sectors (1025 MB)
    > sda: Write Protect is off
    > sda: assuming drive cache: write through
    > sda: sda1
    > Attached scsi removable disk sda at scsi0, channel 0, id 0, lun 0
    > preceeds this in the console both for the failed case and the succeeding case
    > (as I already have the rootdelay=10 param. on the command line as well).
    > I've narrowed this down to another CONFIG_* option, but I can't find which
    > one in tractable time...
    > Does anybody know which CONFIG_* option might contribute to text string
    > root=/dev/sda1 failing while its root=0x0801 cousin works? I've already tried the
    > CONFIG_KALLSYMS one, but no luck. Would this possibly have to do with
    > CONFIG_NLS=m (et al), as I have those as modules, and if so, is this intentional?
    > Thanks,
    > John

    This is expected behavior. The kernel doesn't have a /dev at the time
    it mounts the root fs so it has no idea what /dev/sda1 is. Typically
    lilo will translate /dev/sda1 to 0x0801 automatically for you and pass
    that to the kernel for this reason.

    These days most distributions are using an initrd which the kernel
    mounts as the root fs, and that sets up a minimal /dev and does some
    hardware detection. In that scenario, you can use free form /dev
    strings, assuming that they actually exist by the time the initrd's
    startup scripts finish running.

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      Last update: 2006-02-14 16:46    [W:0.021 / U:4.408 seconds]
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