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[[!meta title="830 MiB RAM Limit"]]

Just like any 32-bit OS without bad tricks, GNU Mach can not cope well with lots
of memory.  Latest versions of the Debian `gnumach` package will limit themselves
to around 1.7 GiB of memory. If you want more, you can twiddle the `VM_MAX_ADDRESS`
limit between kernelland and userland in `i386/include/mach/i386/vm_param.h`.

If you have an older version, or still experience problems with `vmstat` (see
above) reported much less memory than you have, the best is to limit the memory
it can see via GRUB's `upppermem` feature.  Add `uppermem 786432` to GRUB's Hurd
entry in `menu.lst`.