While updating Windows Server 2008 was constantly thrown error code 13EC error. Despite the fact that had 2.83GB free space on hard disk I was unable to proceed with the installation. Nevertheless, extended disk space by additional 5GB and update succeeded.
Make sure you have enough disk space if you encounter this problem.
This error has been thrown while upgrading from Red Hat 6.3 Santiago to Red Hat 6.5
Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)
Pid: 1, comm: swapper Not tainted 2.6.32-431.17.1.el6.i686 #1
 ? panic+0x6e/0x122
 ? mount_block_root+0x1dd/0x274
 ? prepare_namespace+0x14b/0x191
 ? sys_access+0x1f/0x30
 ? kernel_init+0x226/0x234
 ? kernel_init+0x0/0x234
 ? kernel_thread_helper+0x7/0x10
The error was most probably caused by some kernel bug (see references).
- Navigate to /boot/ directory
- Run the command to recreate an initial RAM disk image:
dracut "initramfs-$(uname -r).img" $(uname -r)
- Reboot the machine