Boot Problems after Upgrading Kernel

[sachin_kothari]

I am using Debian Etch on my system having default kernel as 2.6.18.
I downloaded the latest kernel 2.6.21.5 from kernel .org and compiled and installed it.
Everything was fine till here.
I rebooted my system and when i try to boot from the new kernel i get this error message

VFS: Cannot open root device "hda3" or unknown-block(0,0)
Please append a correct "root=" boot option
Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)

I rebooted to my old kernel finally.
Help me boot to my new kernel.

[The Unknown]

As root, in your old kernel, delete the new one and try reupdating using your package manager from the terminal. For example i updated my kernel in Fedora using this in the terminal:

yum update kernel

yum is the package manager for RedHat/Fedora. Also your problem may be because some dependencies for the kernel were not updated. yum downloaded 3 dependencies to be updated.

[sachin_kothari]

how do u do that in debian?

[The Unknown]

Originally Posted by sachin_kothari

how do u do that in debian?

Which packman is installed? dpkg or apt-get?

See this googled result if it helps you: http://www.google.com/search?hl=en&c...update&spell=1

[sachin_kothari]

i got what the problem is. but no solution yet.
the problem is

title		Debian GNU/Linux, kernel 2.6.21.5
root		(hd0,2)
kernel		/boot/vmlinuz-2.6.21.5 root=/dev/hda3 ro 
savedefault

title		Debian GNU/Linux, kernel 2.6.18-4-k7
root		(hd0,2)
kernel		/boot/vmlinuz-2.6.18-4-k7 root=/dev/hda3 ro 
initrd		/boot/initrd.img-2.6.18-4-k7
savedefault

the initrd entry is missing in the new kernel.
how do i get this entry?
how do i create the initrd.img file?

[praka123]

if u made the kernel debian way(its easy!) u can make initrd image by appending "--initrd" to the end of make-kpkg kernel_image kernel_headers to get initrd generated.EDIT:U need to check in kernel menuconfig "CONFIG_BLK_DEV_INITRD=y" to enable generation of initrd.normally it works as it just copies ur current kernels /boot/config-2.xx as /usr/src/.config which supports initrd generation.else u can generate initrd image(tried longback) using tools like yaird,mkinitrd,mkinitramfs etc.u can make a kernel that doesnt need initrd.mostly initrd is used when file system support is made as modules.make it compiled into the kernel with (*) symbol.
Debian uses patched kernel-source which can be obtained via apt as apt-get install linux-source-*
http://howtoforge.com got nice explanation on debian/ubuntu custom kernel compilation.else install "newbiedoc" from apt.
do research "man make-kpkg" and "man for initrd tools" u need to manually copy the initrd image to /boot directory and it needs to match kernel version exactly if u generate initrd the non-debian way.GIYF.always use the debian way for kernel compiling.it generates packages(.deb) for kernel image,headers,modules,initrd and more.
initrd guides:
http://wiki.linuxquestions.org/wiki/Mkinitrd
http://www.redhat.com/docs/manuals/l...el-initrd.html
http://www.faqs.org/docs/evms/x3834.html

[sachin_kothari]

i did what u told appended --initrd at the end of make-kpfg.
the initrd entry is now ok.

but now a new problem
while booting i go this error

Begin: Waiting for root file system ... ...

nothing happens after that.

[The Unknown]

Did you try my suggestion?

[sachin_kothari]

yes i used dpkg, that problem is solved. but what about my new problem?

[The Unknown]

Sorry, i can't understand it.

[mehulved]

What file system are you using? And how did you compile the new kernel?

[sachin_kothari]

ext3
and i used this tutorial for compiling
http://www.holtmann.org/linux/kernel/debian.html
with a change of appending --initrd to make-kpkg

[praka123]

the guide u r following is quiet old and for 2.4 kernels and seems obsolete.use the one at http://howtoforge.com and debian itself has a package called newbiedoc which installs a complete guide for debian including kernel compiling the debian way too.
http://howtoforge.com/roll_a_kernel_debian_ubuntu_way
http://howtoforge.com/kernel_compilation_debian_etch
the error may be due to fs support not built as @mehul said.
go to ur /usr/src/.config or ur new kernel's /boot/config-2.6.xx to check below options be there.this kernel below uses initrd.u can check initrd by mounting it as cpio file(mostly.earlier kernels differ).

CONFIG_EXT2_FS=m
CONFIG_EXT2_FS_XATTR=y
CONFIG_EXT2_FS_POSIX_ACL=y
CONFIG_EXT2_FS_SECURITY=y
# CONFIG_EXT2_FS_XIP is not set
CONFIG_EXT3_FS=m
CONFIG_EXT3_FS_XATTR=y
CONFIG_EXT3_FS_POSIX_ACL=y
CONFIG_EXT3_FS_SECURITY=y

[sachin_kothari]

the config file shows all the options exactly as you mentioned.
anyway i will be using the new tutorial u provided for kernel compilation.
will post the results after that.
thankyou.

edit: the new tutorial worked exactly fine.
i have now booted into my new kernel.
thanks all for all the help.