I am trying to boot from 3.11.1 kernel image on my system having Ubuntu 12.04 (kernel 3.2.0-53)I used make defconfig and then compiled, placed the image in /boot, updated GRUB, and then rebooted.On rebooting, I am getting the following messages :EXT4-fs (sda1) : couldnt mount as ext3 due to feature incompatibilitiesEXT4-fs (sda1) : couldnt mount as ext2 due to feature incompatibilitiesinit : unable to create device: /dev/kmsgRoot filesystem check failedWhat went wrong? If the kernel knows the filesystem is ext4 which I think it does because of the EXT4-fs (sda1), why is it being mounted as ext3/2 ?/etc/fstab :# /etc/fstab: static file system information.## Use 'blkid' to print the universally unique identifier for a# device; this may be used with UUID= as a more robust way to name devices# that works even if disks are added and removed. See fstab(5).## <file system> <mount point>   <type>  <options>       <dump>  <pass>proc            /proc           proc    nodev,noexec,nosuid 0       0# / was on /dev/sda1 during installationUUID=7be51edc-99ae-4e6e-b863-2bef9e4adb22 /               ext4    errors=remount-ro 0       1# /home was on /dev/sda4 during installationUUID=e4b936e5-e1c5-4146-9710-03b0d6dfdea2 /home           ext4    defaults        0       2# swap was on /dev/sda3 during installationUUID=10d012d1-bbba-43f4-8e8a-8aa493435acb none            swap    sw              0       0# Move /tmp to RAMtmpfs /tmp tmpfs defaults,noexec,nosuid 0 0grub.cfg entry for image:menuentry 'Ubuntu, with Linux 3.11.1' --class ubuntu --class gnu-linux --class gnu --class os {    recordfail    gfxmode $linux_gfx_mode    insmod gzio    insmod part_msdos    insmod ext2    set root='(hd0,msdos1)'    search --no-floppy --fs-uuid --set=root 7be51edc-99ae-4e6e-b863-2bef9e4adb22    linux   /boot/vmlinuz-3.11.1 root=/dev/sda1 ro   quiet splash $vt_handoff}menuentry 'Ubuntu, with Linux 3.11.1 (recovery mode)' --class ubuntu --class gnu-linux --class gnu --class os {    recordfail    insmod gzio    insmod part_msdos    insmod ext2    set root='(hd0,msdos1)'    search --no-floppy --fs-uuid --set=root 7be51edc-99ae-4e6e-b863-2bef9e4adb22    echo    'Loading Linux 3.11.1 ...'    linux   /boot/vmlinuz-3.11.1 root=/dev/sda1 ro recovery nomodeset }
Why is the kernel boot failing?
linux;linux kernel
You are trying to boot without an initramfs.  You need to create one with update-initramfs -c -k 3.11.1 and then update-grub.