Friday 25 July 2014

PXE Installation on SLES 11

Objective: PXE installation for autoyast

In an effort to help automate OS installation, I had set up a Preboot Execution Environment (PXE) server.

"The Preboot eXecution Environment (PXE, also known as Pre-Execution Environment, or 'pixie') is an environment to boot computers using a network interface independently of available data storage devices (like hard disks) or installed operating systems."

Environment: SLES 11

I had already discusses how PXE works in my earlier posts where I had installed PXE environment for kick-starting the Redhat/CentOS flavors. If the reader is interested to know how PXE is configured on Redhat/CentOS - click here

Change Plan:

1. Create an ISO from the DVD installation media.
2. Mount the ISO permanently(/etc/fstab) to a particular mount point directory structure which is accessed through server, instead of extracting images. This could be more efficient in storage utilization.
3. Add a software repository for the web-server/ISO image which you have created.
4. Install packages like TFTP, DHCP, APACHE, SYSLINUX if they were not installed by default.
5. Modify TFTP and DHCP configurations as to lease IP addresses according to your environment you are building your enterprise server.
6. Poweron the destination host, boot from the LAN in which NIC makes a request to the DHCP which in-turns provides with information like(IP, subnet, gateway...etc), additionally provides the TFTP location from where it has to get the booting image.

I assume the reader would be aware of creating an ISO image, mounting it permanently, also would be skipping the package installations.

I would be providing more of the configuration details along with the screen shots, which could be helpful incase if you are configuring from " YAST "

Executions :

I had mounted by ISO image on /srv/www/htdocs/sles/11/x86_64 and has added into my repository as below shown, 

Repository Additions :

(Yast -> Software Repositories -> Add -> HTTP -> Server and Directory )

 Repository Name
                           (x) Edit Parts of the URL  
  │            ( ) FTP            (x) HTTP            
 Server Name                                   
 Directory on Server
  │[x] Anonymous                                      
  │User Name                                          

TFTP Enable/Configurations :

Install/enable TFTP and make a boot image directory(/tftpboot), as below :

(Yast -> Network Services -> TFTP Server )

  ( ) Disable
  (x) Enable

  Boot Image Directory

  /tftpboot                  [Browse...]

  [ ] Open Port in Firewall  [Firewall Details...]
  Firewall is disabled

                     [View Log]

DHCP configurations :

Once DHCP is installed on the server, use DHCP server wizard.

Pic 1 :

Domain Name

Primary Name server IP

                                            [ Next ]

Pic 2 :

IP Address Range
First IP Address           Last IP Address   

                                             [ Next ]

Pic 3 :

Service start
[X] When Booting
[ ] Manually

Pic 4: 

Global Options                        

    │Option                               │Value                    
    │ddns-update-style                    │none                     
    │ddns-updates                         │Off                      
    │authoritative                        │On                       
    │log-facility                         │local7                   
    │default-lease-time                   │14400                    
    │option domain-name                   │""            
    │option domain-name-servers           │           
Pic 5 :

Subnet Configuration                                        

    Network Address                                 Network Mask                             

    │Option          │Value                                                      
    │range           │                 
    │next-server     │                                        
    │filename        │"pxelinux.0"                                    
    │option routers  │              

                                                    Click OK and then finish

- Creating a directory structure for TFTP server

mkdir -p /tftpboot/pxelinux.cfg
mkdir -p /tftpboot/sles/11/x86_64

- Copy necessary files for boot to the TFTP server directory structure:

# cd /srv/www/htdocs/sles/11/x86_64/boot/x86_64/loader/
# cp linux initrd message biostest memtest /tftboot/sles/11/x86_64/
# cp /usr/share/syslinux/pxelinux.0 /tftpboot/
# cp /usr/share/syslinux/menu.c32 /tftpboot/

- Create a default menu as below :

#  cat /tftpboot/pxelinux.cfg/default 
default menu.c32
prompt 0
timeout 100

LABEL sles11sp3
KERNEL sles/11/x86_64/linux
APPEND initrd=sles/11/x86_64/initrd splash=silent showopts install= ramdisk_size=65536 

- Below would be the skeleton for our configured TFTP server.

# ls -lar /tftpboot/*

-rw-r--r-- 1 root root 16462 Jul 24 18:14 /tftpboot/pxelinux.0
-rw-r--r-- 1 root root 57140 Jul 24 18:14 /tftpboot/menu.c32

total 12
drwxr-xr-x 3 root root 4096 Jul 24 18:23 11
drwxr-xr-x 4 root root 4096 Jul 24 18:23 ..
drwxr-xr-x 3 root root 4096 Jul 24 18:23 .

total 12
-rw-r--r-- 1 root root  669 Jul 25 11:07 default
drwxr-xr-x 4 root root 4096 Jul 24 18:23 ..
drwxr-xr-x 2 root root 4096 Jul 25 11:07 .

- On BIOS booting press F12, and select LAN(l) to further boot from the media.

Hence we could conclude that the PXE installation is successful and in my further posts I would configure an autoyast file to PXE which would automate SLES.
Thank you for reading and re-sharing.

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