booting problem after kernel update
 

After I updated kernel from 2.6.9-22.EL to 2.6.23 on AS4 Redhat, it couldn't boot from the new kernel. That's all steps I did :
1. cd /usr/src
2. gzip -cd linux-2.6.23.tar.gz | tar xvf -
3. make O=/root/me/build/kernel menuconfig(use the default configurations,didn't change anything)
4. make O=/root/me/build/kernel
5. make O=/root/me/build/kernel modules_install install

well,it's all appears on the screen as it booting:
Booting 'Red Hat Enterprise Linux AS(2.6.23)'
root (hd0,9)
Filesystem type is ext2fs,partition type 0x83
kernel /boot/vmlinuz-2.6.23 ro root=LABEL= / rhgb quiet
[Linux-bzImage, setup=0x2c00,size=ox190988]
initrd /boot/initrd-2.6.23.img
[Linux-initrd @ 0x1f83000, 0x5cb64 bytes]
Unpressing Linux... OK, booting the kernel.
Red Hat nash version 4.2.1.6 starting.
mkrootdev: label /not found
mount: error 2 mounting ext2
mount: error 2 mounting none
switchroot: mount failed:22
umount /initrd/dev faild: 2
kernel panic-not sysncing: Attempted to kill init!

and this is my 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 (hd0,9)
# kernel /boot/vmlinuz-version ro root=/dev/sda10
# initrd /boot/initrd-version.img
#boot=/dev/sda
default=1
timeout=5
splashimage=(hd0,9)/boot/grub/splash.xpm.gz
hiddenmenu
title Red Hat Enterprise Linux AS (2.6.23)
root (hd0,9)
kernel /boot/vmlinuz-2.6.23 ro root=LABEL=/ rhgb quiet
initrd /boot/initrd-2.6.23.img
title Red Hat Enterprise Linux AS (2.6.9-22.EL)
root (hd0,9)
kernel /boot/vmlinuz-2.6.9-22.EL ro root=LABEL=/ rhgb quiet
initrd /boot/initrd-2.6.9-22.EL.img
title Other
rootnoverify (hd0,0)
chainloader +1
I can't figure out what's the problem now : (

You forgot at least one step (the important one) try again. the steps in order are;

make mrproper
make oldconfig
make menuconfig (or xconfig or gconfig here)
make
make modules_install
make install

Just so you know the default kernel configuration as supplied in the vanilla kernel sources will not build a working kernel on a Red Hat system. This is why one neds to run make oldconfig or copy the /boot/config-<version-number> file to the kernel source tree;
cp /boot/config-<version number> .config

make oldconfig is not sufficient between mayor changes as it has been from 2.6.9 to 2.6.23, important parts in kernel config are moved and make oldconfig target is not designed to cope with this.
Why don't you get a new kernel from Red Hat?

mkrootdev: label /not found

This error could be a couple things. One your new initrd image may not have the drivers for your disks so it never see the / partition. Also it could just be that the label is not present on the disk partition. Try editing the grub line and replace root=LABEL=/ with root=/dev/<root partition>. If that works then you probably just need to add a label / to that partition with tune2fs. If you still are having problems I would boot your old kernel and follow the build steps provided by the other posters.

Hi,I followed the build steps you advised for several times,using make oldconfig the first time and cp /boot/config-2.6.9-22.EL .config the second time,but neither succeeded with the same phenomenon during booting. as to make menuconfig, i choosed exit directly , didn't use the last two options "Load the alternate file" and "save the alternate file " .
When it rebooted after I replaced root=LABEL=/ with root=/dev/sda10 in grub.conf, the error msg changed slightly from "mount: error 2 mounting ext2 error " to "mount: error 6 mounting ext2".
still need some hints to resolve the problem.

did you compile in support for ext2 filesystem?

problem resoved
 

This problem was solved months ago, The reason was that I didn't include the support for IDE hard driver in the compile options.Though it appears sda but not hda in the system,so i took it granted that it was a SCSI hard disk but not an IDE hard disk. Though I still wonder why it simulating a SCSI harddisk while there's really an IDE harddisk.

They changed it to sda for everything awhile ago