Starting a FAI installation using kexec

[Torsten Schlabach]

Hi all!

Did anyone ever try to use kexec to start a FAI installation?

My question is related to:

http://faiwiki.informatik.uni-koeln.de/index.php/Using_FAI_to_install_a_root_Server

In other words:

We get servers which have some random Linux image on them. We don't have 
physical access to those servers and we cannot modify and DHCP settings. 
So no PXE based install, no USB stick install, etc.


In the past we have been using the method as described on the Wiki page; 
basically made the boot loader on the installed server boot the 
back-than FAI specific install kernel which then mounted the NFS root 
over the Internet and took it from there.


Now in the newer FAI versions there are no special install kernels any 
more. We took a look at what kernel parameters will be used in a PXE 
setup and tried to use the very same parameters with kexec; just it does 
not work for whatever reason. It's hard to tell what exactly goes wrong 
as the result of the kexec call is basically that the server is no 
longer reachable, does not try to mount the NFS root (we watch the NFS 
server) and also isn't pingable. Though I am not sure if a kernel level 
static IP config (using the ip=... kernel parameter) would make the box 
reply to a ping at all.


Currently, our kexec command looks like this:

kexec \
-l /boot/vmlinuz-2.6.26-2-686 \
--append="boot=live 
ip=xx.xx.xx.xx:yy.yy.yy.yy:zz.zz.zz.zz:255.255.255.0:ourhostname:eth0:off 
root=/dev/nfs nfsroot=aa.aa.aa.aa:/srv/fai/nfsroot 
FAI_FLAGS=sshd,createvt -m /tmp/fai_floppy_dir" \

--initrd="/boot/initrd.img-2.6.26-2-686"

Any thoughts or pointers?

Some docs about mounting the root FS via NFS state that you need to have 
NFS support compiled statically into the kernel, but I understand this 
is no longer valid, is it?


Regards,
Torsten

Re: Starting a FAI installation using kexec

[Henning Sprang]

Torsten Schlabach wrote:
> We get servers which have some random Linux image on them. We don't have
> physical access to those servers and we cannot modify and DHCP settings.
> So no PXE based install, no USB stick install, etc.

I might not fully understand your case, but on an already
basic-installed system, I'd simply run fai softupdate.

Wasn't kexec some system for changing the running kernel without reboot?

Henning

Re: Starting a FAI installation using kexec

[Jean Spirat]

I might not fully understand your case, but on an already
basic-installed system, I'd simply run fai softupdate.

Wasn't kexec some system for changing the running kernel without reboot?

Henning

  
i think the goal here is to take any machine from a provider that you do 
not control via dhcp or pxe and use fai anyway to reinstall it from scratch.


If you knwo how i am interested :)


regards,
Jean.

concerning fai-chboot command

[Rajesh pant]

hello all,
could anyone give me a detailed format of FAI-CHBOOT command.
i know i can go through manual pages but the thing is that i am not getting
how to use it.
And i have an assignment to install a machine using fai by this evening.


One more thing to ask there is no default file inside
/srv/tftp/fai/pxelinux.cfg.
if you could give me a file format of this file it will be helpful, if this
file is require to perform an automatic installation.
eagerly waiting for help and suggestions.
thank you.