Am Sonntag, 20. August 2006 11:07 schrieb Mag. Leonhard Landrock: > Hi! > > I'm nearly finished with my fisrt LFS installation. :-) Nevertheless I > still have some problems booting the new system. :-( > > My problem: > ======== > > When trying to boot my LFS kernel, it starts and finally gets stuck with > the following error: > > VFS: Cannot open root device "sdb3" or unknown-block (0,0) > Please append a correct "root" boot option > Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block > (0,0)
Now I can present the solution. :-) Are very special thank you to Ken Moffat! He gave the most important hint. Let me repeat his saying: " Possibly, passing a rootdelay argument to grub might help, see http://www.reactivated.net/weblog/archives/2005/11/booting-linux-userland-from-an-external-usb-flash-disk/ (yes, I know ithat site is about booting from flash, but it might be worth trying)." So to solve the problem one has to add "rootdelay=10" (or whatever time in seconds) as a kernel parameter. OK now, back to my sucessful configuration. ;-) Here comes the data of my installation: ======================== My PC has one internal scsi hard disk (/dev/sda)) and an external usb hard disk (/dev/sdb). My LFS root is on the usb hard disk. My "normal" Linux system: ================ partitions: --------------- # <file system> <mount point> <type> <options> <dump> <pass> /dev/sda2 / reiserfs notail 0 1 /dev/sda3 none swap sw 0 0 boot loader: ------------------ GRUB installed in the MBR of scsi hard disk (/dev/sda). "/boot/grub/menu.lst": ----------------------------------- I have the following entry for booting my "LFS GRUB": # This entry added by Leonhard Landrock for a non-linux OS # on /dev/sdb3 title Linux from Scratch root (hd1,2) savedefault makeactive chainloader +1 My LFS system: ========== (part of) linux kernel configuration: ------------------------------------------------------ File systems ---> <*> Ext3 journalling file system support [*] Ext3 extended attributes [*] Ext3 POSIX Access Control Lists [*] Ext3 Security Labels Device Drivers ---> USB support ---> <*> Support for Host-side USB [*] USB verbose debug messages [*] USB device file system <*> EHCI HCD (USB 2.0) support <M> OHCI HCD support <*> UHCI HCD (most Intel and VIA) support <*> USB Mass Storage support [*] USB Mass Storage verbose debug (part of) linux kernel configuration in other words: ---------------------------------------------------------------------------- root:/# grep SCSI /boot/config-2.6.16.27 | grep -v "is not set" CONFIG_BLK_DEV_IDESCSI=y # SCSI device support CONFIG_SCSI=y CONFIG_SCSI_PROC_FS=y # SCSI support type (disk, tape, CD-ROM) # Some SCSI devices (e.g. CD jukebox) support multiple LUNs CONFIG_SCSI_CONSTANTS=y CONFIG_SCSI_LOGGING=y # SCSI Transport Attributes CONFIG_SCSI_SPI_ATTRS=y # SCSI low-level drivers CONFIG_SCSI_AIC7XXX=y CONFIG_SCSI_SATA=y CONFIG_SCSI_ATA_PIIX=y CONFIG_SCSI_SATA_SX4=m CONFIG_SCSI_SATA_SIL=m CONFIG_SCSI_SATA_SIL24=m CONFIG_SCSI_SATA_SIS=m CONFIG_SCSI_SATA_INTEL_COMBINED=y # NOTE: USB_STORAGE enables SCSI, and 'SCSI disk support' root:/# grep USB /boot/config-2.6.16.27 | grep -v "is not set" # USB devices CONFIG_SND_USB_AUDIO=m # USB support CONFIG_USB_ARCH_HAS_HCD=y CONFIG_USB_ARCH_HAS_OHCI=y CONFIG_USB=y CONFIG_USB_DEBUG=y # Miscellaneous USB options CONFIG_USB_DEVICEFS=y # USB Host Controller Drivers CONFIG_USB_EHCI_HCD=y CONFIG_USB_OHCI_HCD=y CONFIG_USB_OHCI_LITTLE_ENDIAN=y CONFIG_USB_UHCI_HCD=y # USB Device Class drivers CONFIG_USB_PRINTER=y # NOTE: USB_STORAGE enables SCSI, and 'SCSI disk support' # may also be needed; see USB_STORAGE Help for more information CONFIG_USB_STORAGE=y CONFIG_USB_STORAGE_DEBUG=y # USB Input Devices CONFIG_USB_HID=y CONFIG_USB_HIDINPUT=y CONFIG_USB_HIDDEV=y CONFIG_USB_EGALAX=m # USB Imaging devices # USB Multimedia devices # USB Network Adapters CONFIG_USB_MON=y # USB port drivers # USB Serial Converter support # USB Miscellaneous drivers CONFIG_USB_CYTHERM=m CONFIG_USB_PHIDGETSERVO=m # USB DSL modem support # USB Gadget Support partitions: --------------- # file system mount-point type options dump fsck # order /dev/sdb3 / ext3 defaults 1 1 /dev/sda3 none swap sw 0 0 boot loader: ------------------ GRUB installed in the “boot sector” of the LFS partition (/dev/sdb3). Note: As necessary I used the command setup (hd1,2). "/boot/grub/menu.lst": ----------------------------------- # Begin /boot/grub/menu.lst # By default boot the first menu entry. default 0 # Allow 30 seconds before booting the default. timeout 30 # Use prettier colors. color green/black light-green/black # The first entry is for LFS. title LFS 6.2 root (hd1,2) kernel /boot/lfskernel-2.6.16.27 root=/dev/sdb3 rootdelay=10 bootkbd=de boot # This is a divider, added to separate the menu items below from the LFS # ones. title Other operating systems: root # This entry for a non-linux OS on /dev/sda1 title Microsoft Windows 2000 Professional root (hd0,0) savedefault makeactive chainloader +1 # This entry for another GRUB on /dev/sda title GRUB at sda root (hd0) savedefault makeactive chainloader +1 Well, that's all. :-) I do hope it can be useful in the future. Kind regards, Leonhard. PS: Once again a special thanks to everyone who supported me during my (long) journey on LFS. 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