We have a dedicated server with software RAID1 and one of the disk failed recently. The disk was replaced but after rebuilding the array and rebooting the server freezes with a Kernel Panic message No filesystem could mount root, tried: reiserfs ext3 ext2 cramfs msdos vfat iso9660 romfs fuseblk xfs Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(9,1) The filesystem on both disks is ext4. It seems the kernel can't load ext4 support. Is there any way to add ext4 support or do I need to recompile a new kernel again ? Interesting point that before disk replacement all was fine. The kernel is a stock kernel bzImage-2.6.34.6-xxxx-grs-ipv6-64 from our provider OVH Kind regards,