xCAT-genesis-builder is a utility for building base initrd images for deploying diskless nodes in your cluster. This tool is required only if you have the intention of deploying diskless nodes within your xCAT cluster.

Background

For every architecture in your cluster, be it x86_64, ppc64, or arm, you need to have a default initrd image for performing the initial boot and deploying the diskless operating system.

If for some reason, the versions included in the xCAT repository are insufficient, you can simply run this utility on the target architecture which will build an RPM designed for the target architecture. You can then transfer that RPM to your xCAT servers, install it, and then rebuild the various netboot images.

Pre-requisites

The xCAT-genesis-builder package is designed to be run from a Red Hat compatible operating system that support the Red Hat Package Manager (rpm) development tools. The script buildrpm will attempt to install some of these core packages if they are not already present.

Instructions

First, you need to clone the xcat-core repo to the target architecture using the following command:

git clone -b master https://github.com/xcat2/xcat-core.git

Once there, you can choose to either build the entire package, or more simply, do the following (assuming 2.16.10 is your xCAT version):

cd xcat-core/xCAT-genesis-builder
sed -i 's/%%REPLACE_CURRENT_VERSION%%/2.16.10/g' xCAT-genesis-base.spec
buildrpm

If this command is successful, runs error free, it will generate an RPM that you can transfer to your xCAT server and install and then rebuild your netboot images prior to deploying the netboot images to your nodes.

The RPM will be placed into the following directory /root/rpmbuild/RPMS/noarch if the build is successful.

When running the buildrpm the output should look similar to the following:

[root@vmhost6 xcat-core]# cd xCAT-genesis-builder
[root@vmhost6 xCAT-genesis-builder]# ./buildrpm
Last metadata expiration check: 3:03:21 ago on Fri 27 Aug 2021 06:07:01 AM EDT.
Package rpmdevtools-8.10-8.el8.noarch is already installed.
Package rpm-build-4.14.3-14.el8_4.x86_64 is already installed.
Package screen-4.6.2-12.el8.x86_64 is already installed.
Package lldpad-1.0.1-13.git036e314.el8.x86_64 is already installed.
Package mstflint-4.15.0-1.el8.x86_64 is already installed.
Dependencies resolved.
Nothing to do.
Complete!
Last metadata expiration check: 3:03:23 ago on Fri 27 Aug 2021 06:07:01 AM EDT.
Package efibootmgr-16-1.el8.x86_64 is already installed.
Package bc-1.07.1-5.el8.x86_64 is already installed.
Dependencies resolved.
Nothing to do.
Complete!
/root/xcat-core/xCAT-genesis-builder
cp: -r not specified; omitting directory '/root/xcat-core/xCAT-genesis-builder/debian'
Creating the initramfs in /tmp/xcatgenesis.351827.rfs using dracut ...

Expanding the initramfs into /tmp/xcatgenesis.351827/opt/xcat/share/xcat/netboot/genesis/x86_64/fs ...
623218 blocks
Adding perl libary /usr/share/perl5
Adding perl libary /usr/lib64/perl5
Adding kernel /boot/vmlinuz-x86_64 ...
/root/xcat-core/xCAT-genesis-builder
Tarring /tmp/xcatgenesis.351827/opt into /root/rpmbuild/SOURCES/xCAT-genesis-base-x86_64.tar.bz2 ...
Building xCAT-genesis-base rpm from /root/rpmbuild/SOURCES/xCAT-genesis-base-x86_64.tar.bz2 and /root/xcat-core/xCAT-genesis-builder/xCAT-genesis-base.spec ...
Executing(%prep): /bin/sh -e /var/tmp/rpm-tmp.z5jzb9
+ umask 022
+ cd /root/rpmbuild/BUILD
+ exit 0
Executing(%build): /bin/sh -e /var/tmp/rpm-tmp.Q5Rg87
+ umask 022
+ cd /root/rpmbuild/BUILD
+ exit 0
Executing(%install): /bin/sh -e /var/tmp/rpm-tmp.F7t435
+ umask 022
+ cd /root/rpmbuild/BUILD
+ '[' /root/rpmbuild/BUILDROOT/xCAT-genesis-base-x86_64-2.16.10-snap202108270912.x86_64 '!=' / ']'
+ rm -rf /root/rpmbuild/BUILDROOT/xCAT-genesis-base-x86_64-2.16.10-snap202108270912.x86_64
++ dirname /root/rpmbuild/BUILDROOT/xCAT-genesis-base-x86_64-2.16.10-snap202108270912.x86_64
+ mkdir -p /root/rpmbuild/BUILDROOT
+ mkdir /root/rpmbuild/BUILDROOT/xCAT-genesis-base-x86_64-2.16.10-snap202108270912.x86_64
+ rm -rf /root/rpmbuild/BUILDROOT/xCAT-genesis-base-x86_64-2.16.10-snap202108270912.x86_64
+ mkdir -p /root/rpmbuild/BUILDROOT/xCAT-genesis-base-x86_64-2.16.10-snap202108270912.x86_64
+ cd /root/rpmbuild/BUILDROOT/xCAT-genesis-base-x86_64-2.16.10-snap202108270912.x86_64
+ tar jxf /root/rpmbuild/SOURCES/xCAT-genesis-base-x86_64.tar.bz2
+ cd -
/root/rpmbuild/BUILD
+ :
Processing files: xCAT-genesis-base-x86_64-2.16.10-snap202108270912.noarch
Provides: xCAT-genesis-base-x86_64 = 2:2.16.10-snap202108270912
Requires(interp): /bin/sh
Requires(rpmlib): rpmlib(BuiltinLuaScripts) <= 4.2.2-1 rpmlib(CompressedFileNames) <= 3.0.4-1 rpmlib(FileDigests) <= 4.6.0-1 rpmlib(PartialHardlinkSets) <= 4.0.4-1 rpmlib(PayloadFilesHavePrefix) <= 4.0-1
Requires(post): /bin/sh
Conflicts: xCAT-genesis-scripts-x86_64 < 1:2.13.10
warning: Arch dependent binaries in noarch package
Checking for unpackaged file(s): /usr/lib/rpm/check-files /root/rpmbuild/BUILDROOT/xCAT-genesis-base-x86_64-2.16.10-snap202108270912.x86_64
Wrote: /root/rpmbuild/SRPMS/xCAT-genesis-base-x86_64-2.16.10-snap202108270912.src.rpm
Wrote: /root/rpmbuild/RPMS/noarch/xCAT-genesis-base-x86_64-2.16.10-snap202108270912.noarch.rpm
Executing(%clean): /bin/sh -e /var/tmp/rpm-tmp.yShjx5
+ umask 022
+ cd /root/rpmbuild/BUILD
+ /usr/bin/rm -rf /root/rpmbuild/BUILDROOT/xCAT-genesis-base-x86_64-2.16.10-snap202108270912.x86_64
+ exit 0

Once you transfer the RPM to your xCAT server, you should install it. However, if there is already an xCAT-genesis-base-* RPM for your architecture installed, you will have to uninstall it first using the command below, assuming x86_64 architecture. We use the --nodeps option as the uninstall will fail due to other dependencies.

rpm -e --nodeps xCAT-genesis-base-x86_64*

To install the new RPM, issue the following command, using the 2.16.10 example from above:

rpm -ivh xCAT-genesis-base*.rpm

Now, assuming that the architecture that you have built the xCAT-genesis-base for was ppc64, you would then, on the xCAT server run the following command:

mknb ppc64

At this point in time, you can re-generate your netboot images by running the following commands:

rmimage rhels8.4.0-ppc64le-netboot-image
genimage rhels8.4.0-ppc64le-netboot-image
packimage rhels8.4.0-ppc64le-netboot-image

Finally, attempt a re-imaging of a host using the following command:

rinstall hostname
rcons hostname

If you rcons into the hosts, you can watch the actual initilization of the operating system with the resulting netboot image.

Open Source License

xCAT is made available under the EPL license: https://opensource.org/licenses/eclipse-1.0.php

Developers

Want to help? Check out the developers guide!