I have just built a new gentoo box and was at the moment of glory, the reboot. I have only complete a gentoo install once before and have used that ever since. I go to boot and it runs through its normal boot until i get the message

VFS: Cannot open root device "sda3" or unknown-block(0,0)
Please append a correct "root=" boot option
Kernel Panic - Not syncing: VFS: Unable to moun root FS on unknown-block (0,0)

I searched around and saw some of the same problem but couldt make anything of them, is it a problem with my grub.conf or is a problem with drivers in my kernel. If you need anymore info please let me know, i couldnt think of a way to post my config files because i am posting from another box.

thanks

The first thing I would try in your case is make sure that your root filesystem is compiled into the kernel (not as a module). Next I would make sure that drivers for the disk controller are also compiled into the kernel. I presume you are using SATA, so make sure you have SATA Support enabled (in the SCSI section) and also any drivers appropriate to the controller manufacturer. Use lspci to find out what you need. Hope that helps.

This message means that the computer cannot find the root-partition, which is normally specified as something like root=/dev/hda3. (I've found that root=LABEL=/ doesn't seem to work for me.)

Remember that the boot loader (LILO, grub) needs to know where the boot partition is (which it apparently does know, since you've gotten this far...), then the Linux kernel must know where the root ("/") partition is. Observe carefully the subtle differences between how a disk-partition is identified to grub vs. Linux.

Boot up a CD-ROM and have a look around. Make sure that the files are where you expect them to be.

As noted, the kernel must be able to recognize the disk-device and it must be able to recognize the filesystem. Some early kernels didn't have support for the "ext3" filesystem, relying upon a mkinitrd to supply it; ditto SCSI. However, most recent distros include ext3 support in the kernel, and some support SCSI.

I will go back and check those when I get home. One thing, i believe I did not load IDE drive support in the kernel, during the menuconfig because I have no IDE HD's, would this make a difference? just a thought

I have checked and rechecked my kernel config and I every thing that should be loaded is loaded, not as modules. I am still getting the same answer, is there a way to post my .config, if i boot the live cd and chroot in to the system? that way some one else could take a look at it and maybe see something i missed.

It's possible that you left something out. Maybe you could do another configuration with make defconfig... saving the existing one of course.

Using the live-CD, verify the assignment of partitions, check the partition table, and make sure that you have identified the boot-device correctly. Verify that /sbin/init and other critical files are present there.

It'll be very enlightening if the live-CD is able to mount the partition, because if the live-CD can do it, the disk kernel should be able to do it too.

Make absolutely sure that the device-specification on the root= parameter is correct! It's dev/hd..., right, not (say) dev/sd...?

Triple-check the configuration. Make triple-sure that the correct device drivers and filesystems are present in the kernel. Look things over .. very .. carefully .. one more time.

I can mount my HD with the live cd with the command mount /dev/sda3 /mnt/gentoo: mount /dev/sda1 /mnt/gentoo/boot

I am not sure what you mean by root= parameter is correct! It's dev/hd..., right, not (say) dev/sd...?