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acummings 08-02-2007 12:29 AM

SW12. Two kernels howto boot either 1 of 2
 
Hi. Currently running huge-smp

want to try generic-smp (without overwriting) so I can use lilo to boot huge

I currently see 3 symlinks in /boot

The vmlinuz and the map symlinks are no problem I know how to handle for these in lilo.conf for the generic (the 2nd) kernel.

But in /boot there is a config symlink points to config for huge-smp

man lilo.conf does not show a config= option.

So, is this a concern? If so, how do I point to the config that matches the kernel I'm booting?

--
Alan.

todders 08-02-2007 12:39 AM

hello
to boot the two seperate kernels look in /boot and read the README.initrd and make a initrd for the generic smp kernel.

my entry in lilo.conf is as follows for the generic smp kernel.

image = /boot/vmlinuz-generic-smp-2.6.21.5-smp
initrd = /boot/initrd.gz
root = /dev/hdc1
label = Linux-Smp
read-only

you will have to change the root = to point to your hardrive.

i have had no problems with symlinks or anything else buy following just the README.initrd,you must make sure though after updating lilo.conf that you run lilo as root to update correctly.

regards

todders

onebuck 08-02-2007 08:01 AM

Quote:

Originally Posted by acummings
Hi. Currently running huge-smp

want to try generic-smp (without overwriting) so I can use lilo to boot huge

I currently see 3 symlinks in /boot

The vmlinuz and the map symlinks are no problem I know how to handle for these in lilo.conf for the generic (the 2nd) kernel.

But in /boot there is a config symlink points to config for huge-smp

man lilo.conf does not show a config= option.

So, is this a concern? If so, how do I point to the config that matches the kernel I'm booting?

--
Alan.

Hi,

You will need to edit your bootloader configure file. For '/etc/lilo.conf';
Code:

#

#07-08-07 gws 22:30
# Linux bootable partition config begins
image = /boot/vmlinuz-generic-smp-2.6.21.5-smp
  initrd=/boot/initrd.gz
  root = /dev/hda3
  label = Linux
  read-only
# Linux bootable partition config ends

# Linux bootable partition config begins
image = /boot/vmlinuz-mod-generic-smp-2.6.21.55-smp
  root = /dev/hda3
  label = LinuxNew
  read-only
# Linux bootable partition config ends

you see two stanzas in my example, one for the new (second) and one for the old kernel. After you add the new stanza and save the '/etc/lilo.conf', you should do;

Code:

~#lilo -v -t -b /dev/your_device        #test the '/etc/lilo.conf'
                                        #correct if you have errors then
~#lilo -v -b /dev/your_device          #write the lilo

Once the lilo is written then you should have your kernel options at boot.

Road_map 08-02-2007 08:34 AM

Possible problems with applications who were compiled with one kernel or another. This is an example:
This /etc/lilo.conf file work fine:
Code:

# Linux bootable partition config begins
image = /boot/vmlinuz-generic-2.6.21.5
  initrd = /boot/initrd.gz
  root = /dev/hda3
  label = Slackware
  read-only  # Partitions should be mounted read-only for checking
# Linux bootable partition config ends
# Linux bootable partition config begins
image = /boot/vmlinuz-huge-smp-2.6.21.5-smp
#  initrd = /boot/initrd.gz
  root = /dev/hda3
  label = Slack_new
  read-only  # Partitions should be mounted read-only for checking
# Linux bootable partition config ends

but VMware Server and ATi proprietary drivers need to be reconfigured or reinstalled every time I switch between huge and generic kernel.

acummings 08-02-2007 01:47 PM

It appears then that I need not concern/worry over the map nor the config symlinks that are in /boot

That is a guess on my part due to I guess that all that is needed is:

image = /boot/vmlinuz-generic-2.6.21.5

along with the other that has already already been shared about in the lilo.conf

I guess the above image = line suffices due to if any map or config info is needed that the path to correct map and config are in this particular kernel

If so, then there's no reason to have map and config symlinks in /boot

So, perhaps I should be asking the question:

I have a Slack 12 installation running huge-smp

Why did it put map and config symlinks in /boot

??

simcox1 08-02-2007 02:49 PM

I think that both generic and huge smp kernels are installed by default. So you simply need to add an entry to lilo.conf if you went with the default during install, and want to switch over to the generic kernel. You don't need to alter anything in the boot/ directory, as long as the symlinks which are in there match your lilo.conf entries. The 'config' files list the kernel configuration and are not used by lilo.

blejach 08-22-2007 10:32 AM

why change to generic kernel? i know its smaller, but what are advantages of smaller kernel? speed? memory consumption?
what runs slower if speed is the factor? bootup?
i believe todays computers are fast enough, and there is no big diference in speed between those two kernels... i tried both, and i cant seem to notice the diference in speed

MQMan 08-22-2007 10:42 AM

To answer the OPs original question. You can ignore the config file. It's a copy of the kernel configuration used to build the kernel and modules. I guess Pat put a copy in /boot, just as a "placeholder", as you can only have one copy where it's really needed, in /usr/src/linux, and so, can copy the "correct" one, as .config, when you want to do your own kernel compile.

Cheers.


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