Quote:
Originally Posted by lemonlaw95
i just installed fedora 9, but realized that i had installed the x86 version (it came on a dvd in linux format magazine). i didn't know that the "only-3gb-of-ram-for-x86" applied to linux,
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It only applies to some kernel builds of 32bit Linux.
You can solve the problem by switching to a PAE kernel. I'm pretty sure there is a Fedora package you can install that is the PAE kernel.
Quote:
is there a way to switch to the x86_64 version without downloading and reinstalling it?
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I'm nearly sure there is no way to switch to a 64bit kernel without a complete reinstall of the distribution.
I'm sure you can switch to a PAE kernel by changing only the kernel with no need to reinstall anything else.
If for some reason you can't install a package for a PAE kernel, the next alternative would be to install the various packages needed to do a kernel recompile and add the PAE support yourself. That still would be less disruptive (and less to download) than switching to a 64 bit kernel.
Quote:
Originally Posted by serafean
most of them have "hacks" that overcome this.
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PAE is not a "hack" it is an option in 32bit that makes a very clean change in the memory mapping data structure. A similar (but larger) change is non optional for 64bit mode (so the trivial "extra overhead" you might read about for PAE is a subset of the related extra overhead for the same aspect of 64bit mode, and even there is still trivial).
There is a much uglier hack (as a build-time kernel option) to provide more than 1GB kernel virtual memory in order to have room for data structures for a much larger amounts of ram (I think over 16GB). That version of the kernel should be avoided (use 64bit instead).