summaryrefslogtreecommitdiff
path: root/faq/ram_limit.mdwn
blob: 8e13f321dbf365a741fbb3d2a5623ef85647212f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
[[!meta copyright="Copyright © 2007, 2008, 2013 Free Software Foundation,
Inc."]]

[[!meta license="""[[!toggle id="license" text="GFDL 1.2+"]][[!toggleable
id="license" text="Permission is granted to copy, distribute and/or modify this
document under the terms of the GNU Free Documentation License, Version 1.2 or
any later version published by the Free Software Foundation; with no Invariant
Sections, no Front-Cover Texts, and no Back-Cover Texts.  A copy of the license
is included in the section entitled [[GNU Free Documentation
License|/fdl]]."]]"""]]

[[!tag faq/support]]

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

The 830MB RAM limit has been removed, but 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 3 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`, but glibc and the hurd servers will not cope
well with less than 1 GB.

There is a [[64-bit port|open_issues/64-bit_port]] in progress.

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`.