View source for Boot error "Block device /dev/sdaX is not a valid root device"

'''Problem Description'''

Linux fails to boot


== Symptoms / Error messages ==

at this point the kernel has loaded but can't mount the root partition

console errors
 Activating mdev
 Block device /dev/sdaX is not a valid root device...
 Count not find the roo block device in .
 
at the shell prompt, list of /dev shows there are NO sd devices
 ls /dev/sd*


== Root cause ==
Kernel lacks correct drivers for the boot / hard drive controller.

== Solution ==
 recompile the linux kernel with the appropriate drivers.  Hardware can be determined with utilities such as lsusb & lspci run from a boot cd / usb.
 
[[category:boot]]