Upgrading kernel used in PXE boot

[Cris Rhea]

> From: Eric Smith <eric at trueblade.com>
> Date: Thu, 07 Feb 2008 20:50:09 -0500
> Subject: Re: Upgrading kernel used in PXE boot
> 
> Eric Smith wrote:
> >So my question is:  How do I create a new initrd.img and vmlinuz (that 
> >came in the isolinux directory) to be a new kernel?  It's apparently not 
> >as simple as copying these files from a running system.
> 
> And yes, I realize this might not be the best list for this question, 
> but it's the best I could think of, since people here are no doubt 
> familiar with the issue.  If you know of a better venue for this 
> question, please let me know.
> 
> Eric.

I haven't used the tools the others have suggested, but since you're in a 
PXEboot environment, yes, it can be as simple as using the vmlinux and
initrd.img file from a patched/running system...

The tough part is always making the ramdisk image-- getting all the correct 
drivers included... you seem to have figured this part out already...

For example, in my situation (fighting an Anaconda bug), I boot an older release,
then upgrade at the end of the install process:

default linux
label linux
        kernel vmlinuz-4.4vault
        append initrd=initrd.img-4.4vault load_ramdisk=1 ksdevice=eth0 ks=ftp://clustersw/ks/ks-wsnode-4.4vault.cfg

I used to do this all the time when people built monolithic kernels to handle new/oddball
hardware. Now, you just need to make sure the right modules are available in the 
ramdisk image.

There may be other gotchas along the way (it may complain that the booted kernel doesn't
match the distribution), but if your goal is to have a new kernel booted to start
the install process, this should do it...

HTH.

--- Cris

-- 
 Cristopher J. Rhea                     
 Mayo Clinic - Research Computing Facility
 200 First St SW, Rochester, MN 55905
 crhea at Mayo.EDU
 (507) 284-0587