Procedures for updating the PXE boot kernel

Background

The Dell R620 received in December, 2013, have an E2650 v2 processor. This is not supported by the kernel (2.6.32-279.14.1) that ships with the Rocks 6.1 rolls. The procedure below will rebuild the initrd and vmlinuz files used during the PXE boot process to the kernel actually running on our Rocks front ends, 2.6.32-358.6.2.

Reference for this was found in the Rocks Twiki.

Cookbook following the above directions

• cd
• mkdir newinitrd
• cd newinitrd
• lzma -d < /tftpboot/pxelinux/initrd.img-6.1-x86_64 |cpio -id
• rm -rf modules/2.6.32-279.14.1.el6.x86_64
• cp -R /lib/modules/2.6.32-358.6.2.el6.x86_64 modules/
• find . | sudo cpio --create --format='newc' | lzma -9 > ../initrd.img-2.6.32-358.6.2.el6.x86_64
• cd ..
• cp initrd.img-2.6.32-358.6.2.el6.x86_64 /tftpboot/pxelinux
• cp /boot/vmlinuz-2.6.32-358.6.2.el6.x86_64 /tftpboot/pxelinux/
• du -sk newinitrd|awk '{print int($1/1000)*1000+1000}'

The size of the newinitrd directory was 164000. We will use this value to set the install boot option parameters. The Rocks Twiki directions above assume we are making a new boot action, but instead, we just want to replace the default boot action. To see what parameters are set in place in advance, and "just in case", do this as directed.

[root@umrocks6 ~]# rocks list bootaction|grep ^install
install:          vmlinuz-6.1-x86_64    initrd.img-6.1-x86_64 ks ramdisk_size=150000 lang= devfs=nomount pxe kssendmac selinux=0 noipv6 ksdevice=bootif        
install headless: vmlinuz-6.1-x86_64    initrd.img-6.1-x86_64 ks ramdisk_size=150000 lang= devfs=nomount pxe kssendmac selinux=0 noipv6 headless vnc ksdevice=bootif

Replace the default "install" action as follows:

[root@umrocks6 ~]# rocks add bootaction action=install kernel=vmlinuz-2.6.32-358.6.2.el6.x86_64 ramdisk=initrd.img-2.6.32-358.6.2.el6.x86_64 args="ks ramdisk_size=164000 lang= devfs=nomount pxe kssendmac selinux=0 noipv6 ksdevice=bootif"

Now, go ahead and PXEboot/build any R620.

-- BobBall - 29 Jan 2014