Hi, After upgrading (using apt-get method) my system from 3.0.3 ( kernel 2.4.21-20.EL ) to 3.0.4 ( kernel 2.4.21-27.0.2.EL.XFS) , the system could not boot. Error message: /********************************************/ VFS : cannot open root device ... Please append a correct "root=" boot option Kernel panic : VFS Unable to mount root ... /********************************************/ Solution: Change file /boot/initrd-2.4.21-27.0.2.EL.XFS.img, by adding BusLogic.o, scsi_mod.o and sd_mod.o in lib directory. Note: I upgraded 2 systems from 3.0.3 to 3.0.4 using the same procedure, apt-get. It has work perfecly for the 1st system and I had got this bug on the second one. Both system are running on VMWare. Cheers, Cannot boot after apt-get upgrade-kernel Jean