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View Full Version : [SOLVED] 11.04 PAE Kernel Loads by Default



VideoRoy
April 28th, 2011, 11:09 PM
Next little problem. After Upgrading to 11.04 32bit, the PAE Kernel loads by default. This would be great except it hangs probably due to graphics not loaded properly.

Regardless I do not want to use PAE Kernel on this dev system I have and luckily it looks like the Generic Kernel of the right version is in a sub-Menu called Older Linux Versions.

I have played with Grub2 before making minor changes but this one is a little beyond me. How can I move the regular Generic Kernel from the sub-Menu and make it my default Grub2 kernel so I boot to it automatically.

Thanks for any pointers!

IPEX-731BA5DD06
April 29th, 2011, 05:34 AM
Simplistic method, I guess, is to use Synaptic package manager, install the NON PAE kernel 1st, then remove the PAE KERNEL.

List under a search for Linux, and it'll list the Full PAE kernel, flag to uninstall once you have the new kernel loaded, and just re-boot.

VideoRoy
April 29th, 2011, 01:58 PM
Simplistic method, I guess, is to use Synaptic package manager, install the NON PAE kernel 1st, then remove the PAE KERNEL.

List under a search for Linux, and it'll list the Full PAE kernel, flag to uninstall once you have the new kernel loaded, and just re-boot.

Thanks for the reply IPEX but I was probably not very clear. The correct kernel is loaded on the system, but it is buried in a Grub2 sub-menu so it cannot be listed as the default.

BTW, I have now upgraded 2 completely different types of systems and the default PAE kernel does not load on either of them. One is a dual processor (not dual core) high end workstation used for product development / test with an Nvidia Quattro video card. The second is a Toshiba laptop with ATI graphics chip. Both have 4 gigs of RAM. I am pretty sure the boot problems are graphics related on both but I really just do not want to use the PAE kernel any way.

I have yet one other 64 bit development system with 8gigs RAM and on that I run 64 bit version of Ubuntu and it works fine.

I have to question why the Ubuntu team decided to load the PAE kernel by default during this upgrades. I cannot believe I have really unique systems that are having the problems booting. I am guessing you will see lots of people with the same issues.

I will try the PAE kernels later once I get everything stable and figure out why they do not boot, but for now I am going to dig into Grub2 docs and figure out how to promote the sub-menu kernels to the main menu and make them the default.

VideoRoy
April 29th, 2011, 03:08 PM
Simplistic method, I guess, is to use Synaptic package manager, install the NON PAE kernel 1st, then remove the PAE KERNEL.

List under a search for Linux, and it'll list the Full PAE kernel, flag to uninstall once you have the new kernel loaded, and just re-boot.

IPEX you were right!

I spent about an hour reading and found out more information about how Grub2 1.99 works with sub-menus. In the end since I already had the correct version non-PAE kernel loaded, I went to Synaptic searched "linux-generic-pae" and removed all of the installed entries. In my case it was 3 and you have to remove them all or else it will not solve the problem.

Once these are gone, the normal generic kernal is promoted to the main menu automatically during boot time without having to edit any Grub2 files.

Pretty simple after all but probably not really obvious since submenus are a new feature in Grub2.

Thanks.

abuelmagd
May 1st, 2011, 01:18 PM
You are not an exception. I also have a 4GB memory system with an ATI card and X fails to load when I run the PAE kernel. I also figured out the presence of the non-pae kernel in the sub menu but was looking for a way to make it default. So I will follow your lead.

To tell you the truth I was not interested into switching the default kernel because of the convenience factor when booting the system. I was more interested in what happens when upgrades are available. I was worried that the non pae kernel would never get upgraded and the system would only keep upgrading to pae kernels.

Edit: After looking into this further it seems that pae support depends on the generic kernel. So this means upgrades would have happened normally with no issues. I stilled removed the packages for the convenience factor. :)

VideoRoy
May 3rd, 2011, 04:41 AM
You are not an exception. I also have a 4GB memory system with an ATI card and X fails to load when I run the PAE kernel. I also figured out the presence of the non-pae kernel in the sub menu but was looking for a way to make it default. So I will follow your lead.

To tell you the truth I was not interested into switching the default kernel because of the convenience factor when booting the system. I was more interested in what happens when upgrades are available. I was worried that the non pae kernel would never get upgraded and the system would only keep upgrading to pae kernels.

Edit: After looking into this further it seems that pae support depends on the generic kernel. So this means upgrades would have happened normally with no issues. I stilled removed the packages for the convenience factor. :)
I was thinking about this as well when the next kernel update occurs. But as long as the previous kernel is kept, there is always a fall back.

Waiting to see what the behavior will be :D