Hello, I seem to be always getting stuck in the new kernel booting. The problem is with mounting of the root file system. I don't have the log of the messages but, I guess, these were the messages reported VFS: Cannot open root device ............ Please append a correct "root=" boot option; here are the available partitions: Device: sda driver: sd ....... list of all partitions on sda, including correct size, offset of each parition ....... Device sdb driver: sr Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0) Backtrace: It reported the correct list of sda partitions, including the driver name as sd. I have a SATA disk and the root partition has ext4 file system. The ext2/3/4 code is compiled as a part of the kernel. $ df -kh / Filesystem Size Used Avail Use% Mounted on /dev/sda1 459G 13G 423G 3% / As far as I can understand, as it is showing the correct list of partitions, the problem is not with the block device driver. But I am not sure, why it is failing to mount the file system when ext4 is also part of the kernel. grub.cfg file. menuentry 'Ubuntu, with Linux 2.6.37-rc6+' --class ubuntu --class gnu-linux --class gnu --class os { recordfail insmod part_msdos insmod ext2 set root='(hd0,msdos5)' search --no-floppy --fs-uuid --set ab9dfe8f-8e58-43ca-b16f-a42e0f02da72 linux /vmlinuz-2.6.37-rc6+ root=UUID=01432597-18e7-4609-9f85-3fad1d762ddc ro iommu=1 initrd /initrd.img-2.6.37-rc6+ } menuentry 'Ubuntu, with Linux 2.6.35-22-generic' --class ubuntu --class gnu-linux --class gnu --class os { recordfail insmod part_msdos insmod ext2 set root='(hd0,msdos5)' search --no-floppy --fs-uuid --set ab9dfe8f-8e58-43ca-b16f-a42e0f02da72 linux /vmlinuz-2.6.35-22-generic root=UUID=01432597-18e7-4609-9f85-3fad1d762ddc ro iommu=1 quiet splash initrd /initrd.img-2.6.35-22-generic } The kernel 2.6.35-22-generic boots correctly. Thanks and Regards, Prasad