Reg. Loading older kernel

[padmajarv]

Hi all,
I am new to the kernel stuff and I had to load the RTC module support for the kernel 2.6.9-42.0.2.EL. After doing make and make modules_install , the PC 's ethernet interface is now not coming up. infact the device eth0 is not there in the ifconfig. Only the loop back address is present. also now I cant see any modules under the /lib/modules/`kernel-version`. So if i try to load the ethernet module 8139too.ko with modprobe or do a depmod, it gives error that this module is not found.

I dont know how to bring the PC out of this state without losing the current applications. When the changes were made to the .config when I did make menuconfig, is it possible that the system would have saved a copy of the old config file? because I see a config file by name .config.old under the persently loaded kernel in the /usr/src/. If it is so, is it possible to revert to the old configuration? Please let me know how this can be done.......

Also, there is another kernel version called 2.6.9-34.EL or something under /usr/src/kernels. If the .config.old does not work, can I change the kernel version to 2.6.9-34.EL? If so please provide me any important info and the steps to do so.

Finally I read somewhere that we can recover the current kernel from /boot directory. How is this possible.
Thanks in advance for all the help,
Awaiting your reply,
Padmaja

[cyberinstru]

Please paste the output of the following here:

1. Do

cat /etc/grub.conf

2.

ls /lib/modules

3.

uname -r

4.

ls /boot

[padmajarv]

Thank You for coming back so soon:
Here is what you asked for:

cat /etc/grub.conf

#Note that you do not have to rerun grub after making changes to this file
#NOTICE: You have a /boot partition. This means that
# all the kernel and initrd paths are relative to /boot/ , e.g.,
# root (hd0,0) kernel /vmlinuz-version ro root=/dev/VolGroup00/LogVol00
# initrd /initrd-version.img
#boot= /dev/hda
default=0
timeout=5
Splashimage=(hd0,0) /grub/splash.xpm.gz
hidden menu
Title CentOS (2.6.0-42.0.2.EL)
root (hd0,0)
Kernel /vmlinuz-2.6.9-42.0.2.EL ro root /dev/VloGroup00/LogVol00 rhgb quiet
initrd /initrd-2.6.9-42.0.2.EL.img
Title CentOS -4 i386 (2.6.9-34.EL)
root (hd0,0)
Kernel /Vmlinuz-2.6.9-34.EL ro root= /dev/VolGroup00/LogVol00 rhgb quiet


************************************************** *******

ls /lib/modules

2.6.9-34.EL
2.6.9-34.EL.ELsmp
2.6.9-34.ELhugemem
2.6.9-42.0.2.EL
2.6.9-42.0.2.ELsmp
2.6.9-42.0.2.ELhugemem
Kabi-4.0-0

uname -r
2.6.9-42.0.2.EL

ls/boot

boot.b
chain.b
config-2.6.9-34.EL
config-2.6.9-42.0.2.EL
grub (folder)
initrd-2.6.9-42.0.2.EL.img
initrd-2.6.9-34.EL.img
lost+found(dir)
memtest86+-1.26
message

Please let me know if there is a way to use the same kernel 2.6.9-42.0.2.EL with all the applications intact. I do not want to go to other kernel types available if possible.

Thank You,
Padmaja

[cyberinstru]

Please let me know if there is a way to use the same kernel 2.6.9-42.0.2.EL with all the applications intact. I do not want to go to other kernel types available if possible.

Fine. You said in you previous thread that you dnt see any modules.

. also now I cant see any modules under the /lib/modules/`kernel-version`

While choosing modules, did u compile all the modules statically?

If yes, then you will not be having any modules in the directory.

If not, go to the source of that kernel (2.6.9-42.0.2.EL), and do

make modules_install

and see if your modules are in place /lib/modules/2.6.9-42.0.2.EL/kernel/

Once you hve got all the modules in place, do mkinitrd and re-boot ur system.

Please let us know, if u still face any problems.

[padmajarv]

Hello,

Thanks again for your reply. I could not understand a few things from what you mentioned:

***While choosing modules, did u compile all the modules statically? If yes, then you will not be having any modules in the directory. If not, go to the source of that kernel (2.6.9-42.0.2.EL), and do make modules_install ***


I dont know what it means by compiling all the modules statically. After choosing RTC as a modules from menuconfig, I saved the changes to the kernel and then I did a make modules_install. then rebooted the system. Since then the ethernet interface does nt come up. And I cant see any modules under the current kernel version under /lib/modules/. Does that mean I have compiled the modules statically? If so what should I do to get back all the modules? As you mentioned, I tried make modules_install but still i cant see any modules under /lib/modules/'kernel-release'. Of course I didnt do the mkinitrd and reboot the system, because I thought to consult before doing anything.

Please let me know what I should do to get all the modules back and to have the current kernel version running without losing any applications.....

Thanks again,
Padmaja

[cyberinstru]

Can you post your .config file here? It is a hidden file, present in your kernel source directory (2.6.9-42.0.2.EL).

Fine. If you cud not post the entire .config here, please let us know the following clarifications:

Open .config file

vi .config

In that file, could see anything like this?

CONFIG_8139TOO=m

If yes, then RealTek module is compiled dynamically. Instead of 'm', if you see 'y', then that module is compiled statically.

Please let me know what I should do to get all the modules back and to have the current kernel version running without losing any applications.....

Please do this as the last option:

1. Do

make menuconfig

2. Select
General Setup-->

3. Select
Local version - append to kernel release

4. Put some identifier string - for ex: "-Try1"

5. Do required changes - goto Device Drivers -> Network Device Support -> Ethernet -> and choose the card name and put 'M'

6. Save the changes

7. Compile kernel "make bzImage"

8. Compile modules "make modules"

9. Install modules "make modules_install"

10. Copy bzImage to /boot dir - "cp arch/i386/boot/bzImage /boot/bzImage-2.6.9-42.0.2.EL-Try1"

11. Copy System.map to /boot dir - "cp System.map /boot/System.map-2.6.9-42.0.2.EL-Try1"

12. Do mkinitrd - "mkinitrd -v /boot/initrd-2.6.9-42.0.2.EL-Try1.img 2.6.9-42.0.2.EL-Try1"

13. Add conf to grub.conf

#Note that you do not have to rerun grub after making changes to this file
#NOTICE: You have a /boot partition. This means that
# all the kernel and initrd paths are relative to /boot/ , e.g.,
# root (hd0,0) kernel /vmlinuz-version ro root=/dev/VolGroup00/LogVol00
# initrd /initrd-version.img
#boot= /dev/hda
default=0
timeout=5
Splashimage=(hd0,0) /grub/splash.xpm.gz
hidden menu
Title CentOS (2.6.0-42.0.2.EL)
root (hd0,0)
Kernel /vmlinuz-2.6.9-42.0.2.EL ro root /dev/VloGroup00/LogVol00 rhgb quiet
initrd /initrd-2.6.9-42.0.2.EL.img
Title CentOS -4 i386 (2.6.9-34.EL)
root (hd0,0)
Kernel /Vmlinuz-2.6.9-34.EL ro root= /dev/VolGroup00/LogVol00 rhgb quiet

Title CentOS (2.6.0-42.0.2.EL-Try1)
root (hd0,0)
Kernel /bzImage-2.6.9-42.0.2.EL-Try1 ro root /dev/VloGroup00/LogVol00 rhgb quiet
initrd /initrd-2.6.9-42.0.2.EL-Try1.img

14. See that your /lib/modules/2.6.9-42.0.2.EL-Try1/kernel path has all the modules in it

15. Re-boot the system - choose this kernel

N.B. Some typo might be thr in it. Please ensure that u dnt follow the typos, if any.

[padmajarv]

Hi,

Before I proceed with the steps that you sent, please let me know about the following things:


1. The hidden .config file has the CONFIG_8139too.ko set to m (module). there are many other things defined as modules in this .config file but none of these modules are present in /lib/modules/kernel-version. This folder is completely empty.

2. There is a config-2.6.9-42.0.2.EL in the /boot directory corresponding to the current kernel version 2.6.9-42.0.2.EL. HOwever, the config file in /boot differs from the hidden .config file in the kernel directory at two places. Is this ok? These are at the places in the files where RTC is defined as a module. Rest of the places, the files are very similar.

3. I do not get a version of kernel to choose while the PC is booting. In fact I did not know that there are so many kernel versions on my PC until I looked into the /usr/src/kernels directory. So if I tag the current kernel with the string as you mentioned by doing menuconfig, will I get the option automatically during boot time to load this kernel? Or is there some code change to LILO that I have to do for the system to display this menu?

4. If by any chance the steps do not work, can i go to the kernel version 2.6.9-34.EL and still have my applications running?

Your help is greatly appreciated.

Thank You,
Padmaja

[padmajarv]

Hi,

Sorry, in the last message I mentioned that the system does not give me any option for choosing the kernel. After sending you the reply, I thought about it and restarted the PC, it was going to set the default kernel and before the timeout, I pressed enter and it then showed me the options:

2.6.9-42.0.2.EL and 2.6.9-34.EL

I chose the second option this time and I did nt get even a single error. The ethernet interface too is now up and i can connect that PC to network and all my applications are also intact..This part of the issue is now solved.. Thank You very much....

Now that I know the system can work with the the lower kernel version, I will try to make the changes to original kernel 2.6.9-42.0.2.EL as you suggested and see if it too can come up and work as before..
For that please let me know if there is a need to change the Lilo boot loader code..

Thanks again for all your help,
Padmaja

[cyberinstru]

a need to change the Lilo boot loader code..

If you r using LILO, u need to edit /etc/lilo.conf and after editing it run lilo

lilo

Before that, get into the source 2.6.9-42.0.2.EL, do "make modules" and do "make modules_install" and check if you have ur modules in /lib/modules/2.6.9-42.0.2.EL path.


If possible, can u paste the output of "make modules_install" here?

[cyberinstru]

To have more time to choose kernel, set timeout to some higher values

For ex:

timeout=20