On Thu, Jan 24, 2013 at 12:46:40AM -0500, Bluejay Adametz wrote:
> >  How does one activate both to appear so that the library packages for both
> > will be put into the system via the GUI?
> 
> You should be able to explicitly install 32-bit versions of libraries
> with something like
>       yum install libblah.i686
> 
> I'm not sure if there's a way to install both bits with one installation.
> 


Historically, the early 64-bit distributions (SL and others) did not include
many important 32-bit packages which had to be "grafted-in" from the
corresponding 32-bit distributions. Many such packages conflicted severely.

But today, the 64-bit distributions of SL contain all the important 32-bit
packages, so there is no need to kludge anything. I.e. there is no need
to enable the 32-bit repos of SL on 64-bit machines. Most likely
the 32-bit packages you want are already there in the 64-bit repository.

Most 32-bit packages that are available are not installed by default. You have to install
them manually using "yum install xxx.i686" as explained by previous poster.

For example, here is the list of 32-bit packages we install to support
cross-compilation of ROOT and related software:
http://www.triumf.info/wiki/DAQwiki/index.php/SLinstall#Install_packages_needed_for_QUARTUS.2C_ROOT.2C_EPICS_and_MIDAS_DAQ

Why would one want 32-bit packages on 64-bit machines:

a) to cross-compile software that has to run on 32-bit hardware (VME processors, etc)
b) to run 3rd party software only available in the 32-bit flavour (commercial software, 64-bit unclean software, etc)

I would say that a modern 64-bit distribution has to include the full 32-bit development
environement. E.g. all "-devel" packages have to come in both flavours.


-- 
Konstantin Olchanski
Data Acquisition Systems: The Bytes Must Flow!
Email: olchansk-at-triumf-dot-ca
Snail mail: 4004 Wesbrook Mall, TRIUMF, Vancouver, B.C., V6T 2A3, Canada