[CentOS] PXE install in a boot on san with LVM environment, fails after reboot

Thu Dec 25 20:34:09 UTC 2014
Damien Gouju <damien at gouju.net>

Hello,

I need to automate installation of CentOS 7.0 using PXE and kickstart. 
My server is diskless, I'm installing CentOS on a 25GB LUN on a FC SAN 
with 4 paths. This LUN is the only one accessible by the server.

Anaconda processes successfully the installation. But on reboot, I get 
stuck on a prompt after BIOS. I think I have an issue with storage 
configuration / bootloader configuration...

I can install it using the ISO, with basic configuration. The 
/root/anaconda-ks.cfg looks like the following (I striped some part, I 
cannot copy past because I have only console access through a secured 
VPN :-/ ):
firstboot --enable
ignoredisk --only-use=mpatha,sdc,sdd,sdb,sda
bootloader --location=mbr --boot-drive=mpatha
autopart --type=lvm
clearpart --all --initlabel --drives=mpatha
%packages
@base
@core
%end

My ks.cfg template is identical (I also cannot attach it 
unfortunately…).

I tried several things like:
- put sda as boot-drive for bootloader (according to 
http://osdir.com/ml/general/2014-09/msg52181.html ), but anaconda fails 
with error that this drive cannot be found. It asks to choose another 
disk, mpatha is the only available.
- same with dm-0 (as /dev/mapper/mpatha is a symlink to /dev/dm-0) but 
anaconda also fails
- add to bootloader « --append="rd.lvm.lv=centos/root 
rd.lvm.lv=centos/swap" »

I also found some post on the web saying that in the « ignoredisk » 
mpatha mustn't be used but disk/by-id/scsi-XXXX (chapter 23.3.2 of RHEL 
7 installation guide), but I don’t know how to manage that.

Is someone ever did that kind of PXE installation, with boot on san & 
LVM, and help me in the kickstart configuration?

Any help would be highly appreciated!

Best regards,
Damien