15/04/2012 17:06 -0700, Konstantin Olchanski wrote:
> On Sun, Apr 15, 2012 at 02:46:49PM -0500, Kevin K wrote:
> > Depending on what special features you might use on your system
> (virtualization, third party drivers), it might be possible to build a
> kernel from kernel.org.  I've tried this in the past but since the
> latest kernel still didn't properly support the broken hardware I
> didn't pursue it further.
> 
> 
> Yes, what you say is possible. I run a few SL5 machines with a custom
> built 2.6.34 kernel (the funny hardware requires non-default access
> method to PCI config space).
> 
> Last I remember, it was not too hard to build a vanilla linux kernel that
> booted the SL5 userland. I do remember a few gotchas - some boot scripts expected
> some drivers to be loadable modules (I had them compiled into the kernel),
> autofs did not work because /dev/random broke (SL5 kernel uses the network
> as source of randomness, but vanilla kernel does not, and there is no other
> hardware present in the system). Took maybe half a day to sort this all out.
> (I am not looking forward to repeat this with the 3.x kernels).
> 
> 
> > On Apr 15, 2012, at 1:46 PM, Keith Lofstrom wrote:
> > 
> > > I'm running S.L. 5.6 on a few machines, and have grown somewhat
> > > dependent on it.  However, there are features in the kernel 
> > > that comes with 6.2 (like USB3) which I would like to have.
> > > 
> > > Is it possible to upgrade just the kernel and associated modules
> > > and "miscellaneous"?
> > > 
> > > I assume this is tricky, and fraught with dangers, and the usual
> > > cautions (make backups, work on a copy of the disk, tweak yum 
> > > updates so they won't regress the 2.6.32 kernel, etc) apply.
> 
> 
> I do not see any danger or special caution - if an SL6 kernel would boot
> SL5 userland, it should run okey. But you will run into trouble with
> userland stuff required to support the kernel - udev, mkinitrd, mdadm & co -
> the SL5 stock tools might be too old for the recent kernels.
> 
> That said, where I am, lack of support for new hardware is the main reason
> we move from SL3 to SL4 to SL5 to SL6.
> 
> For new kernel features, you can run mongrel systems with mismatched
> userland and kernels, but at some point the cost of diverging
> from the mainstream becomes bigger than the cost of moving
> all your apps to latest SL. (At which point effort of creating
> and maintaining a mongrel system is wasted; while the effort
> of moving apps to latest SL is mostly in understanding your apps
> and in keeping *them* up to date, which you should do anyway,
> regardless).

The most simple solution for this problem -- using virtualized SL5
installation on SL6 host.

> K.O.
> 
> 
> 
> > > 
> > > For now, I just want to know whether this is worthy of further
> > > consideration, or instead I should set aside a few weeks to
> > > upgrade everything then rebuild a lot of poorly written custom
> > > apps.
> > > 
> > > Keith
> > > 
> > > -- 
> > > Keith Lofstrom          [log in to unmask]         Voice (503)-520-1993
> > > KLIC --- Keith Lofstrom Integrated Circuits --- "Your Ideas in Silicon"
> > > Design Contracting in Bipolar and CMOS - Analog, Digital, and Scan ICs
>