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BIOS PXE boot and installation via Cobbler

Cobbler configuration

A system can be added to Cobbler via either CLI or web interface. 

# cobbler system add --name=hostname --mac=xx:xx:xx:xx:xx:xx --profile=profile_name_ol71 --interface=eth0

The Kernel Options is important to be present if kickstart is used for unattended instalaltion, the URL can be found by selecting a System's View Kickstart and coping the URL.









Upon adding a system in Cobbler, the file /var/lib/tftpboot/pxelinux.cfg/01-<mac_address> will be created, it looks something like ... 
default linux
prompt 0
timeout 1
label linux
 kernel /images/OL-R7-U1-x86_64_BIOS/vmlinuz
 ipappend 2
 append initrd=/images/OL-R7-U1-x86_64_BIOS/initrd.img ksdevice=bootif lang= ks=http://cobbleradmin/cblr/svc/op/ks/system/my-hostname text

NOTES:
A system can be added in the Cobbler without filling info in Networking (Global) and Networking tabs. In this case Cobbler creates the file /var/lib/tftpboot/pxelinux.cfg/<hostname>, so hostname is used instead of MAC address. The prerequisite is that system's DNS record must exists.

Also note, if system's MAC is not defined in Cobbler, the Cobbler presents the profile list to a system. The unattended installation will still happen, since profile has associated kickstart file.

Another case can be if you add a system with its MAC but there is no DNS record for the system, here Cobbler creates the file /var/lib/tftpboot/pxelinux.cfg/<IP_address_in_HEX>

DHCP configuration

The block of code to define system in DHCP configuration can be: 
host my-hostname {
 hardware ethernet 00:21:28:xx:xx:xx;
 fixed-address 10.aa.aa.aa ;
 next-server 10.bb.bb.bb ;
 filename "/pxelinux.0";
 }
The next-server and filename can be defined even as globaloptions.

PXE boot and installation

Power on a system, select Network boot and the unattended installation (using the kickstart file) will start and complete.
If the "network" option is not specified in kickstart file, the ethernet interface will be configured as dhcp client (even Static is selected in System - Networking tab).
In order to have ethernet interface configured with static IP, the example of this line is needed in kickstart file. 

network --device eno1 --bootproto static --ip 10.aa.aa.10 --netmask 255.255.252.0 --gateway 10.aa.aa.1 --nameserver 10.bb.bb.1,10.cc.cc.198 --hostname my-name.company.com

Cobbler configuration

A system can be added to Cobbler via either CLI or web interface.

DHCP configuration

A system is not defined in the DHCP.

PXE boot and installation

Power on a system, select Network boot. Since system is not defined in DHCP, it will get IP address from DHCP pool, then it will contact Cobbler and start unattended installation, after reboot the system will boot with proper IP, assuming a kickstart file has line like: 

network --device eno1 --bootproto static --ip 10.aa.aa.10 --netmask 255.255.252.0 --gateway 10.aa.aa.1 --nameserver 10.bb.bb.1,10.cc.cc.198 --hostname my-name.company.com

Cobbler configuration

A system is nor defined in Cobbler.

DHCP configuration

The block of code to define system in DHCP configuration can be: 
host my-hostname {
 hardware ethernet 00:21:28:xx:xx:xx;
 fixed-address 10.aa.aa.aa ;
 next-server 10.bb.bb.bb ;
 filename "/pxelinux.0";
 }
The next-server and filename can be defined even as globaloptions.

PXE boot and installation

Power on a system, select Network boot. The system will get an IP from DHCP and contact Cobbler.
Since the system is not defined in Cobbler, the list of all Cobbler's profiles will be presented to the system. Select the profile to continue installation. If (local) is selected, the system will try booting from the local disk.

Cobbler configuration

A system is not defined in Cobbler.

DHCP configuration

A system is not defined in DHCP.

PXE boot and installation

Power on a system, select Network boot. The system will get an IP from DHCP range and it will contact Cobbler. Since the system is not defined in Cobbler, the list of all Cobbler's profiles will be presented to the system. Select the profile to continue installation. If (local) is selected, the system will try booting from the local disk.

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