How to create an initrd image on OpenSuSE linux?

Question

/usr/src/linux-3.2.1 # make install
scripts/kconfig/conf --silentoldconfig Kconfig
sh /usr/src/linux-3.2.1/arch/x86/boot/install.sh 3.2.1-12-desktop arch/x86/boot/bzImage \
                System.map "/boot"
You may need to create an initial ramdisk now.

--

/boot # mkinitrd initrd-3.2.1-12-desktop.img 3.2.1-12-desktop

Kernel image:   /boot/vmlinuz-2.6.34-12-desktop
Initrd image:   /boot/initrd-2.6.34-12-desktop
Kernel Modules: <not available>
Could not find map initrd-3.2.1-12-desktop.img/boot/System.map, please specify a correct file with -M.
There was an error generating the initrd (9)

See the error during mkinitrd command. What's the point that I am missing?
What does this mean? Kernel Modules: <not available>

OpenSuse 11.3 64 bit

EDIT1:

I did "make modules".
I copied the System.map file from the /usr/src/linux-3.2.1 directory to /boot, now running initrd command gives the following error:

linux-dopx:/boot # mkinitrd initrd-3.2.1.img 3.2.1-desktop

Kernel image:   /boot/vmlinuz-2.6.34-12-desktop
Initrd image:   /boot/initrd-2.6.34-12-desktop
Kernel Modules: <not available>
Could not find map initrd-3.2.1.img/boot/System.map, please specify a correct file with -M.

Kernel image:   /boot/vmlinuz-3.2.1-12-desktop
Initrd image:   /boot/initrd-3.2.1-12-desktop
Kernel Modules: <not available>
Could not find map initrd-3.2.1.img/boot/System.map, please specify a correct file with -M.

Kernel image:   /boot/vmlinuz-3.2.1-12-desktop.old
Initrd image:   /boot/initrd-3.2.1-12-desktop.old
Kernel Modules: <not available>
Could not find map initrd-3.2.1.img/boot/System.map, please specify a correct file with -M.
There was an error generating the initrd (9)

Solution 1

You should be using mkinitramfs, not mkinitrd. The actual initrd format is obsolete and initramfs is used instead these days, even though it is still called an initrd. Better yet, just use update-initramfs. Also you need to run make modules_install to install the modules.

Solution 2

With OpenSUSE, you can use

yast2 sysconfig

fill in 'INITRD_MODULES' with module you need and apply.

Comments

[bsd]

Which distro? And the comment does say MAY, using Gentoo I don't bother with making an initrd, they're not necessary.

[Aquarius_Girl]

@bdowning sorry, have edited it. :)

[Nikhil Mulley]

btw, I will carve out a seperate question for difference between initrd and initramfs, it will make a good Q&A :-)

[Aquarius_Girl]

mkinitramfs gives command not found on Suse.

[psusi]

@AnishaKaul, I guess Suse has a different tool for building it. Debian based distributions use the initramfs-tools package.

[Aquarius_Girl]

SOLVED: The reason for these errors was that I was trying to make an initrd image before running make modules_install. So, now I ran make modules_install and initrd image got automatically created in /boot.

[Aquarius_Girl]

CONCLUSION: On Kernel 3 onwards we don't have to create an initrd image, it gets created automatically after make modules_install.

[RMuesi]

@AnishaKaul, that is the expected behavior, as documented in the README file of the kernel sources.