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Re: [Condor-users] java machines with > 2gb



On Mon, Sep 15, 2008 at 10:27 PM, Joe Meehean <jmeehean@xxxxxxxxxxx> wrote:
> This issue has everything to do with 32 vs. 64-bit
> operating systems.  With 32-bit OS's no process
> can have more than a 3GB address space.  If you
> need more than 2GB of Java heap space ensure you
> are submitting your job to a 64-bit machine with a
> 64-bit OS.  If you don't need more than 2GB's,
> follow the workaround.

Technically extensions like AWE can allow this - I know of no JVM
vendors that have bothered to do this (it would make heap management
an absolute nightmare).

Also note that, even on 64bit operating systems many vm's actually
still disallow more than 2GB (neither will the .Net runtime) for any
single object on the heap, so if you're trying to stuff everything
into one array (or hashtable which is a single array under the hood)
then going over 2GB won't help.

To the OP: If you're trying to go over 2GB heap and don't get most of
this discussion then you need to start doing some reading up. If you
don't need it go with the workaround like Joe says

Matt