kernel启动问题

yum update kernel*后重启，找不到新内核，查看/etc/grub.conf
# cat /etc/grub.conf
# grub.conf generated by anaconda
#
# Note that you do not have to rerun grub after making changes to this file
# NOTICE:  You do not have a /boot partition.  This means that
#          all kernel and initrd paths are relative to /, eg.
#          root (hd0,0)
#          kernel /boot/vmlinuz-version ro root=/dev/sda1
#          initrd /boot/initrd-[generic-]version.img
#boot=/dev/sda
default=0                                         #default=0表示启动第一个kernel，default=1表示启动第2个，依次类推
timeout=5
splashimage=(hd0,0)/boot/grub/splash.xpm.gz
hiddenmenu
title Red Hat Enterprise Linux Server (2.6.32-478.el6.x86_64)
    root (hd0,0)
    kernel /boot/vmlinuz-2.6.32-478.el6.x86_64 ro root=UUID=2f00636e-676b-4841-97f5-d8a5198338cf rd_NO_LUKS  KEYBOARDTYPE=pc KEYTABLE=us LANG=en_US.UTF-8 processor.max_cstate=1 crashkernel=256M nmi_watchdog=0 console=tty0 console=ttyS0,115200 reboot=pci biosdevname=0 rd_NO_MD SYSFONT=latarcyrheb-sun16 crashkernel=auto rd_NO_LVM rd_NO_DM rhgb quiet
    initrd /boot/initramfs-2.6.32-478.el6.x86_64.img           #如果缺失，看看kernel-devel有没有装

kernel.x86_64                               2.6.32-478.el6              @rhevh6
kernel-devel.x86_64                         2.6.32-478.el6              @rhevh6
kernel-firmware.noarch                      2.6.32-478.el6              @rhevh6
kernel-headers.x86_64                       2.6.32-478.el6              @rhevh6