AMD64 vs i386 on a Dual Opteron Box

Nathan Vidican nvidican at
Wed Oct 12 07:13:39 PDT 2005

We've been encountering some difficulty between 
OpenLDAP/nss/pam/FreeBSD/samba over the past few months and really since 
inception. After countless recompiles of samba, working with samba and 
openldap code, we've traced it to being an issue somwhere between 
freebsd and openldap using threads, a clean compile of openldap without 
using threads runs fine, but still seem to have inconsistency with nss 
portions of it.

The conscencus accross a few different threads on various mailing lists 
seems to be to try running FreeBSD/i386 instead, therefore assuming 
perhaps that there are some issues with threading/openldap/nss_ldap on 
the AMD64/64-bit platform. We're currently running 5.3-RELEASE, I'm 
going to attempt 5.4-RELEASE/amd64 first, if the issues still arises, 
the next step would be to try 5.4-RELEASE/i386, and if the problem still 
exists... then back to trying to debug the whole situation.

So, given the above information, my question is this:

Knowing FreeBSD i386 can be run on AMD64 hardware, is there any 
disadvantage other than the obvious 64-bit support? We're using dual AMD 
Opteron based machines with 2GB ECC registered memory, so memory 
capacity shouldn't be an issue running 32bit, but how about smp support?

Also, if anyone might have another idea or option to go with towards 
fixing the openldap/freebsd issue, that'd be even better still - but to 
be honest I lack the skills, time, and hardware neccessary to accomplish 
this on my own. I'm hoping that something between 5.3-RELEASE and 
5.4-RELEASE can resolv the issue, or at least to isolate it to 
FreeBSD/OpenLDAP/Samba/nss_ldap/? as the cause.

In short, i386 on AMD64 good, bad, why?

Nathan Vidican
nvidican at
Windsor Match Plate & Tool Ltd.

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