Josh, Sounds like a strange problem indeed. Off the top of my head, try running mkinitrd manually for the new kernel (in verbose mode), to make sure that it is preloading all of the modules necessary to boot your / filesystem. Specifically make sure it is loading the raid1 module, and the ext3 module (assuming / is formatted ext3). Also, if your drives are other than regular IDE (scsi or sata), make sure the appropriate scsi or sata modules are getting loaded. To run mkinitrd in verbose mode, just pass it the -v flag. So in this case your command would look like this: mkinitrd -f -v /boot/initrd-2.4.21-20.0.1.ELsmp.img 2.4.21-20.0.1.ELsmp Try that first to make sure the modules are getting loaded. -Ryan