On Fri, Feb 23, 2007 at 10:26:58AM +0000, Santanu Das wrote:
> Hi all,
>
> Now we got 32 new Dell PowerEdge 1950 boxes; all with dual Xenon 5150
> 2.66GHz processor (i.e. Woodcrest) and 8Gb of memory. As, gLite still
> can't cope with 64-bit architecture, then what about addressing all the
> memory on those boxes? Look at:
> http://www.intel.com/technology/intel64/index.htm
>
> It states that a 64 bit OS is needed to address more than 4GB of
> memory. However, as those boxes have 8GB each, implying that we only
> ever use half of the installed memory. Furthermore, Condor's advertising
> all 8GB of installed memory, which may have unfortunate repercussions
> when jobs try to run above the 4GB mark. Any suggestion(s)??
With a PAE enabled kernel you can see more than 4GB although jobs are still
limited to ~3GB of memory and a performance hit of 5-15%.
We are running RHEL4 x86_64 in all of our new machines for some time now
and we don't have any real problems beyond people trying to compile!! binaries
on the fly with their job sumbission and forgetting to use gcc -m32 for the
grid.
So gLite does work under x86_64 in 32bit mode (you do have to be carefull
with 32/64bit versions of perl/python/etc though).
Kostas
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