jaunty 32b cannot see more than 3023M RAM

[Cédric Jeanneret deactivated]

Binary package hint: linux-image-generic

Hi,

It seems that Jaunty cannot see all the RAM in my laptop (installed : 4G, seen : 3023M).
Using another Linux, also 32B, I had to activate some options in the kernel:
 High Memory Support (64G)
in Processor Type and features

as I use a lot of KVM, VMWare and VirtualBox, I really need my system to see all my installed ram. And I can't be in 64B, as my office install all our computers in 32b....

One smart thing : when searching package name while filling this bug, I saw a package named "linux-image-generic-pae".... but apt-cache search linux-image-generic-pae doesn't match anything... that's a pitty...

Informations :
Description: Ubuntu 9.04
Release: 9.04

 dpkg -l | grep linux-image
ii linux-image-2.6.28-13-generic 2.6.28-13.45
ii linux-image-generic 2.6.28.13.17

uname -r
2.6.28-13-generic

Thanks in advance

Regards,

C.

[Cédric Jeanneret deactivated (cjeanneret-c2c-deactivated)]

BTW, while reading /boot/config-2.6.28-13-generic, here's the options to change :

ACTUAL:
CONFIG_HIGHMEM4G=y
# CONFIG_HIGHMEM64G is not set

SHOULD BE
# CONFIG_HIGHMEM4G is not set
CONFIG_HIGHMEM64G=y

Regards,

C.

[Michele Mordenti (micmord)]

Use 2.6.28-13-server kernel if you want HIGHMEM set.

[Cédric Jeanneret deactivated (cjeanneret-c2c-deactivated)]

well, ok.... so workstations aren't supposed to have more than 3G of ram ? I just don't see the point.....

-server works, but that's... stupide.

[Michele Mordenti (micmord)]

I really don't know if it's a bug or a feature on 32bit systems, I am not a ubuntu architect.
I just suggested you a possible workaround.

[Giacomo Catenazzi (cate)]

3GB is the maximum *sane* value of memory for 32-bits architectures. Part of the extra gigabyte is used by hardware (IO-mapped memory, etc).

Having 64GB in 32-bit is a hack (in hardware and software), very slow, and change a lot of interns of linux kernel (all vm part), thus breaking all binary modules. Thus we need two version: one more compatible, and one for much more memory. Considering that 32-bit machines are also the oldest one, we cannot slow down so much the low-end computers (which cannot go to 64-bit).

I really suggest you to go to 64-bit. 64-bit can run 32-bit code (but do some tests to see if ubuntu support all 32bit libraries in 64-bit). You can also run 32-bit virtual machines.

At some point your company need to go at 64-bit, so it is better to think already now how to have the dual bit environment.