Re: running postgres in a ramdisk

It's a hardwired limitation. I currently have an Opteron system with 8GB
of memory running 32-bit Redhat and the max tmpfs I can make is 4GB.

And from reading the below message, it's possible it might still have
the 4GB limit on a 64-bit OS.

http://archive.lug.boulder.co.us/bymonth/2002.08/msg00099.html

Keith Keller wrote:
> On Tue, Oct 14, 2003 at 04:12:22PM -0700, William Yu wrote:
>
>>Tmpfs is dynamically resizable but the big
>>gotcha is that under 32-bit Linux, you're limited to 4GB max for a
>>ramdisk of any type.
>
>
> Hmm, that could be a huge problem--one of our tables is over 4GB. I
> could be wrong, but can the kernel option to support more than 4GB of
> physical memory help here? Or is it a limitation of the ramdisk itself?
> We do tentatively plan on using linux, though a kernel recompile is
> fairly easy for us to do.