Maintenance script: Created page with " === PXE boot patch === (steps for RHEL5 and later) pxeboot start from 2 files: kernel (typically called `vmliuz` and the initrd (called `initrd.img`) to cr..."

2015-08-26T12:28:59Z

Created page with " === PXE boot patch === (steps for RHEL5 and later) *pxeboot start from 2 files: kernel (typically called <tt>vmliuz</tt> and the initrd (called <tt>initrd.img</tt>) *to cr..."

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=== PXE boot patch ===
(steps for RHEL5 and later)
*pxeboot start from 2 files: kernel (typically called <tt>vmliuz</tt> and the initrd (called <tt>initrd.img</tt>)
*to create new pxeboot kernel?
**locate the kernel version used (to download precompiled modules for the correct version)
<pre>
strings vmlinuz |grep '2\.6'
</pre>
**eg
<pre>
[root@localhost test_pxe]# strings vmlinuz |grep '2\.6'
2.6.18-53.el5
2.6.18-53.el5 (mockbuild@builder6.centos.org) #1 SMP Mon Nov 12 02:14:55 EST 2007
</pre>
**set the version and architecture (the variables are used later). eg. for centos 5.1 64-bit
<pre>
KERNEL=2.6.18-53.el5
ARCH=x86_64
</pre>
**3ware modules: 3ware has precompiled modules to boot with at http://www.3ware.com/kb/article.aspx?id=14546. These in general do not include rpms for later kernels, so you have to do that yourself
**get the file, unzip it and locate the .ko file
**you also need the pcitable with identifiers so the hardware is recognised
**XFS
**centos has kernel modules (in rpms) for XFS in centosplus repository
**get the rpms
*to add modules to the initrd
**download the initrd
**become root user
<pre>
su -
</pre>
**prepare
<pre>
HERE=$PWD
mkdir orig initrd-old modules-old
cp initrd.img orig
mv initrd.img initrd-old/initrd.img.gz
cd initrd-old
zcat initrd.img.gz |cpio -i
/bin/rm initrd.img.gz
cp modules/modules.cgz $HERE/modules-old
cd $HERE/modules-old
zcat modules.cgz|cpio -ivd
</pre>
*now you have a directory <tt>$KERNEL/$ARCH</tt>with all current modules. This is the place to add new ones or replace old one.
**3ware
**unzip the .zip files from 3ware site
<pre>
[root@localhost 3ware]# unzip ../191-3w-95xx-9650_9690_rhel5-kernel2.6.18-53.EL5-installdisk-x86_64-9.5-GUID083205f49ac341bc980c5c58ff4f1bc0.zip
Archive: ../191-3w-95xx-9650_9690_rhel5-kernel2.6.18-53.EL5-installdisk-x86_64-9.5-GUID083205f49ac341bc980c5c58ff4f1bc0.zip
inflating: modinfo
inflating: modules.alias
inflating: modules.cgz
inflating: modules.dep
inflating: modules.pcimap
inflating: pci.ids
inflating: pcitable
inflating: Readme
inflating: rhdd
</pre>
**the module you need is in modules.cgz
<pre>
zcat modules.cgz |cpio -ivd
</pre>
**locate the module and copy it to <tt>$HERE/modules-old/$KERNEL/$ARCH/</tt>
**the zip file also comes with a pci.ids file. you now have to compare the contents of this file with the 3ware section of the one in <tt>$HERE/initrd-old/modules/pci.ids</tt>
***if fields are missing, add them
**XFS
**rename the xfs rpm to xfs.rpm (eg:
<pre>
cd $HERE
cp kmod-xfs-0.4-1.2.6.18_53.el5.centos.plus.x86_64.rpm xfs.rpm
</pre>
**then do
<pre>
cd $HERE
mkdir xfs
cd xfs
rpm2cpio ../xfs.rpm |cpio -ivd
</pre>
**you know should have an xfs.ko file
**mind that when using centosplus, the kernel name that is used to compile this module is slightly different from the one in vmlinuz/initrd (it has .centos.plus added). This should not give any issues though
**copy this file to <tt>$HERE/modules-old/$KERNEL/$ARCH/</tt>
*repack the modules
<pre>
cd $HERE/modules-old
/bin/rm modules.cgz
find $KERNEL|cpio -ov -H crc|gzip -c9 > modules.cgz
/bin/rm $HERE/initrd-old/modules/modules.cgz
cp modules.cgz $HERE/initrd-old/modules/modules.cgz
cd $HERE/initrd-old
find . |cpio -o -H newc|gzip > ../initrd.img.new
</pre>
*the new initrd is now in <tt>$HERE/initrd.img.new</tt>

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PXEboot patch - Revision history

Maintenance script: Created page with " === PXE boot patch === (steps for RHEL5 and later) *pxeboot start from 2 files: kernel (typically called vmliuz and the initrd (called initrd.img) *to cr..."

Maintenance script: Created page with " === PXE boot patch === (steps for RHEL5 and later) pxeboot start from 2 files: kernel (typically called `vmliuz` and the initrd (called `initrd.img`) to cr..."