Removing remnants of old kernels

original_jamingrit · 07-14-2008, 02:42 PM

Hey all,

In the past week or so, I've compiled a lot of unsuccessful kernels in my attempts to get one that worked well for my system. It seemed that I was always forgetting to enable some thing while configuring. I've probably built about a dozen. :-P

To build and install, I was just using the basic method as described in the Slackbook, which goes:

Code:

cd /usr/src/linux
make mrproper
#insert fiddling with .config file here
make menuconfig
make bzImage; make modules

##This part was only done the first time;
cp /boot/vmlinuz /boot/vmlinuz.old; cp /boot/System.map /boot/Sysytem.map.old
# and then put a place for the default kernel in GRUB

##The rest was done every time;
cat arch/i386/boot/bzImage > /boot/vmlinuz; cp System.map /boot/System.map
make modules_install
poweroff
#cross fingers

So as you can see from the above, I continually overwrite the old kernels each time I create a new one. But the modules for old kernels remain, since I change the kernel version extension each time (really didn't need to, and probably shouldn't have). I want to know the proper and safest way of removing those by hand. Any advice or opinions?

jailbait · 07-14-2008, 04:11 PM

Quote:

Originally Posted by original_jamingrit

So as you can see from the above, I continually overwrite the old kernels each time I create a new one. But the modules for old kernels remain, since I change the kernel version extension each time (really didn't need to, and probably shouldn't have). I want to know the proper and safest way of removing those by hand. Any advice or opinions?

Each set of modules is in a directory in /lib/modules. The directory names in /lib/modules are the kernel version extension of the kernel that each set of modules corresponds to. So you can delete all of the directories in /lib/modules except the directory which corresponds to the kernel that you are actually using.

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Steve Stites

GushpinBob · 07-14-2008, 11:37 PM

This is how I clean up older kernels and kernel modules.

To remove modules:

Code:

rm -r /lib/modules/VERSION

where VERSION is the kernel's version of which I am removing

To remove the kernel itself:

Code:

rm -r /boot/KERNEL

where KERNEL is your old kernel whether it be named vmlinuz-VERSION or bzImage-VERSION or etc.

Remove the System.map-VERSION from the /boot directory (assuming if anyone still copies their System.map file into boot)

Remove or comment out the lines to boot that old kernel in lilo.conf or GRUB's menu.lst

Finally, remove the old kernel's source directory (though I'd recommend holding on to the sources that came with your distro-supplied kernel). Usually after extracting and building a kernel from source, you're left over with a kernel source directory that can be hundreds of megabytes large. So if your strapped for space look in your /usr/src directory for any old uncompressed kernel build directories

.

EDIT: Don't delete the source dir for your current kernel. Some software that is custom compiled will often check (i.e if you're building 3rd party modules).

original_jamingrit · 07-21-2008, 03:14 PM

Okay, great! Old modules have been removed with no ill effects.

Thanks a lot!