Because I now need full X86-64 functionality, although many binaries are 
still 32 bit.  My workstation changed from a dual-core Intel (HP 
professional unit) to a current 4 core AMD that we built as a kit 
computer in a quality Antec gaming case.  We could not afford (no 
budget, no budget justification) the cost of the equivalent HP.  I have 
an external grant that supplies us with a new Nvidia Tesla GPU compute 
engine (specifications available in private communication if you wish), 
and I then got a grant from Nvidia that included a Tesla C2070 as a 
development node in my own workstation (I use a different Nvidia card 
for graphics, also CUDA capable).  However, to use the Tesla, I needed a 
newer workstation.

I used all of my existing drives, including the CentOS 5 system disk, 
and the machine booted cleanly.  But, this was an interim solution until 
I switch to a full 64 bit implementation (our compute engine will be 
using SL 6 X86-64 as a RHEL 6 clone), and now is the time to switch.  I 
was thinking of switching to Centos 5 X86-64, but it seemed to me if I 
go to all that trouble, I will use RHEL 6 (SL 6 as CentOS 6 is still not 
available in production release).

As part of this grant, we got a number of stereoscopic 3D visualisation 
workstations using the Nvidia system (and thus not suitable for 
individuals with epilepsy) -- we installed SL 6 X86-64 along with 32 bit 
compatibility libraries with no major problems.
(One minor problem I have not yet addressed:  using 32 bit Firefox 4 
current and the current Flash plugin, Flash does not work properly.)

Regards,

Yasha Karant
Director
Institute for Applied Supercomputing
Professor
School of Computer Science and Engineering

URL: http://www.cse.csusb.edu/ykarant/home.html

On 06/16/2011 02:00 PM, Stephan Wiesand wrote:
> On Jun 16, 2011, at 22:03 , Yasha Karant wrote:
>
>> At this point, I must copy a whole number of directories to partitions/drives that do not need to be reformatted (e.g.,  /usr/local, /opt , /home that I keep in separate ext2 partitions) to preserve a number of utilities that I will then cp -pr (or tar) back to whatever SL 6 does.
>
> None of those is safe to keep without reformatting. Why not stay with CentOS5 if preservation is a major objective?
>
>
>