ARRAGGH!

Nearly every time I try and build a new kernel I get this error about it not being able to mount the root file system.
I went and borrowed a RedHat 2.4 kernel configuration, and borrowed some compatible things out of it, and worked it all into a fresh 2.6 configuration file.... but still I get the inability to mount the root filesystem.

Can ANYONE tell me EXACTLY what the heck causes this panic. The plain vanilla 2.6 kernal config already has ext2 and ext3 selected as default... so it's most clearly something else that I am missing.... just what that "something else" is, is what I would like to know.

i used to get that msg as well the thing I selected was on the cpu option there should be an option for standard 86 cpus or something like that it says on the description that it should be selected for distros but that is selected along with the right cpu, anyway I solved it like this not sure if is gonna work on yours

Redhat's default config makes ext3 a module, so you also need to build a new initrd initial ramdisk (man mkinitrd), or change the config so that ext3 gets built into the kernel.