dkms + megaraid_sas and kernel update

[Matt Domsch]

On Fri, May 16, 2008 at 11:02:44AM +0200, Rainer Traut wrote:
> I'm afraid dkms-2.0.19 does not solve the problem.
> 
> Rainer Traut schrieb:
> > Matt Domsch schrieb:
> >> On Thu, May 15, 2008 at 02:15:39PM +0200, Rainer Traut wrote:
> >>> After a kernel update from 2.6.18-53.1.14.el5 to 2.6.18-53.1.19.el5
> >>> I see that none of my dkms installed drivers are used by the new kernel:
> > 
> >> Would you mind installing
> >> http://linux.dell.com/dkms/dkms-2.0.19-1.noarch.rpm, and manually
> >> fixing up dkms's database the way you want (e.g. dkms
> >> install/uninstall commands)?  On next kernel upgrade it
> >> should work as expected...
> > 
> > Ok, thank you.
> > I go trying the rpmforge 2.0.19-2.el5.rf because I have good experience 
> > with this repo. Hope this is fine.
> 
> I uninstalled completely for testing dkms V2.0.19:
> bnx2, megaraid_sas, tg3, dkms2017, kernel-2.6.18-53.1.19.el5 + headers + 
> devel
> 
> I reverted back to kernel 2.6.18-53.1.14.el5 + headers + devel.

thanks for the careful reproduction.


> # dkms status
> megaraid_sas, v00.00.03.16, 2.6.18-53.1.14.el5, x86_64: installed 
> (original_module exists)
> bnx2, 1.7.1c, 2.6.18-53.1.14.el5, x86_64: installed (original_module exists)
> tg3, 3.81c, 2.6.18-53.1.14.el5, x86_64: installed (original_module exists)
> tg3, 3.81c, 2.6.18-53.1.19.el5, x86_64: installed-weak from 
> 2.6.18-53.1.14.el5
> bnx2, 1.7.1c, 2.6.18-53.1.19.el5, x86_64: installed-weak from 
> 2.6.18-53.1.14.el5
> megaraid_sas, v00.00.03.16, 2.6.18-53.1.19.el5, x86_64: installed-weak 
> from 2.6.18-53.1.14.el5

This looks I would expect now.

> So what is the weak-updates stuff if it is not used?

weak-updates is a trick, added to RHEL5, which lets you re-use add-on
kernel modules compiled for slighly earlier kernels still from the
RHEL5 series, because we know that the kernel ABI has not changed.
Rather than compile and install the module for the new kernel, it
maintains a symlink (which you found) for the module from
/lib/modules/${newkernel}/weak-updates/ back to the
/lib/modules/${oldkernel}/extra/ directory.  This is handled
automatically at kernel installation time by the kernel RPM itself.

> And what happens if it is used and a later kernel update removes the 
> /lib/modules/2.6.18-53.1.14.el5/ directory?

I think it's handled, but I forget how.  Jon?


> And why is it not working? :)

What's not working about this now?  Your initrd-2.6.18-53.1.19.el5.img
should have the v00.00.03.16 driver in it now.  No?



-- 
Matt Domsch
Linux Technology Strategist, Dell Office of the CTO
linux.dell.com & www.dell.com/linux