Upgrade zimbra from 32 bit to 64 bit on ubuntu 8.4

[snake_eyes]

Hello,

With reference to my post on ubuntuforums [ubuntu] 12 GB RAM but Ubuntu detect 4 only - Ubuntu Forums, I just wanna your help with the upgrading stage, I have Siemens server as I mentioned with 12 GB on Ubutnu 8.4 32 bit and zimbra 5.0.11 32 bit, in order to force Ubuntu to read the 12 GB, I will go ahead with Ubuntu upgrading: Ubuntu 4GB Ram Limitation and Solution.

I've been checked the migration post: [SOLVED] 32bit to 64bit migration and ATTN: Ubuntu 8.04 Users but doesn't helpful.

I want to upgrade zimbra from 5.0.11 32-bit to 5.0.16 64 bit, so can you share your info with this issue? and your suggestion also?

Cordially,

[snake_eyes]

In additional to my previous post, I want to ask if I want to run:
$ sudo sudo apt-get install linux-headers-server linux-image-server linux-server

So is it required to upgrade zimbra from 32 bit to 64 bit or doesn't matter?

Altough the Operating system will be Ubuntu 8.4 LTS 32 bit with server kernel (Asuuming I upgraded the kenel to 64 bit).

Cordially,

[iway]

You might have a look at: Zimbra on Ubuntu 8.0.4 - severe issues
And also vote for the bug!

[snake_eyes]

I have been finished this task, finnaly I got:

Invalid initial heap size: -Xms4873m
The specified size exceeds the maximum representable size.
Could not create the Java virtual machine.

I ran this command

zmlocalconfig | grep mailboxd_java_heap_memory_percent

the value is 40 (because the RAM is 4 GB), What it supposed to be if the total RAM are 12 GB? please note that I want to add also RAM to be 35 GB.

Cordially,