Wednesday, November 21, 2012

kernel-lt and kernel-ml

And Nux! said "Let there be light" and there was kernel-l(igh)t.

Actually the 'lt' in kernel-lt stands for long term. That is, the kernel-lt package set is based on the long-term, stable branch from the Linux Kernel Archives as opposed to the mainline branch, upon which the  kernel-ml package set is based.

All this started with an innocent-looking request on the ELRepo mailing list:
"Guys, is there a possibility to have the TLS kernels in their own repo 
or would it be just spreading too thin? Maybe some hardlinks as to not 
waste space.. I'm not using the lts kernel but I'm thinking many do and 
they don't want to have the lts kernel updated by the "latest" one."
After a long discussion (of nearly 40 posts) it was decided that the ELRepo Project would provide a long-term kernel, as 'kernel-lt', from the elrepo-kernel repository. Currently the following kernel versions are available:

EL6
kernel-ml 3.6.x
kernel-lt 3.0.x

EL5
kernel-lt 3.0.x

In conclusion we must state our usual disclaimer:
We provide these kernels for hardware testing in an effort to identify
new/updated drivers which can then be targeted for backporting as kmod packages. Meanwhile, these kernels may provide interim relief to people with non-functional hardware. We stress that we consider such kernels as a last resort for those who are unable to get their
hardware working using the RHEL-{5|6} kernel with supplementary kmod packages.

These packages are provided "As-Is" with no implied warranty or
support. Using the kernel-lt may expose your system to security,
performance and/or data corruption issues. Since timely updates may
not be available from the ELRepo Project, the end user has the
ultimate responsibility for deciding whether to continue using the
kernel-lt packages in regular service.

The packages are intentionally named kernel-lt so as not to conflict
with the RHEL-{5|6} kernels and, as such, they may be installed and
updated alongside the regular kernel. The kernel configuration is
based upon a default RHEL-{5|6} configuration with added functionality enabled as appropriate.

If a bug is found when using these kernels, the end user is encouraged
to report it upstream to the Linux Kernel bug tracker [1] and, for our
reference, to the ELRepo bug tracker [2]. By taking such action, the
reporter will be assisting the kernel developers, Red Hat and the Open
Source Community as a whole.
[1] http://bugzilla.kernel.org/
[2] http://elrepo.org/bugs/