Hi Techies,

We have 10 offices (1 HO + 9 sites) with 10 different Domain names. (eg; dom1.com, dom2.com to dom10.com) where dom1.com is the HO. Some of of the sites are using Ex2k3 + AD, some are Ex2k7 + AD and one site is postfix + ldap, and few sites are having hosted mail service.

Now we are planning to move this entire domain to a single domain called "abc.com". So we are really looking for a opensource solution for our entire Infrastructure. If we could propose a good opensource alternative, our Management is ready to accept opensource for its core services. I feel like, this is a great chance to Migrate from MS to Linux... So kindly post your solutions/comments/suggestions.

Existing Infra Details;
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1. 9 offices are working with MS Active Directory and its related servers, like Exchange, ISA, etc. and 1 office is using LDAP as the backend and Linux based Servers like Postfix, Squid, etc.
2. Most users are using MS Outlook (few Entourage and Evolution Clients), most operating systems are Windows7 and XP, few are Mac and Ubuntu
3. Outlook Web Access, Outlook Anywhere, Contacts, Calendar are used by users
4. 10% of users are using mobile services (Blackberry, Iphone, symbian, microsoft mobile)
5. We have totally around 2000 users inclusive of all offices.

Objectives of the Expected Solution;
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1. Unified single domain called abc.com
2. Linux alternative solution for Active Directory services
3. All sites will be having local Mail servers
4. All External Mails to our company should come to our HO, then re routed to the sites users mailboxes or to the HO internal users mailboxes
5. Each sites users mailboxes should be stored in the local mail server located in that corresponding site
6. When the user is transfered, mailbox should also move to the new location
7. Global Address book should be available from Desktop / web / Mobile devices
8. Should support Blackberry BES service
9. Mail, Contact, Calender, etc should work from Windows, Mac and Linux desktops
10. Web mail support
11. Smooth Migration
- Existing mails should be available in the new setup
- Auto response when a mail hits the old email-id, informing then of the new email-id
- Minimal downtime


We are looking for information to go with a solution which can be used to replace MS with Linux. It will be really helpful if anyone who can share his thoughts/experience to acheive our objectives.

Thanks in Advance...

Most of the major Linux distributions can handle what you are after. They are all cable of running various services, web, email, web mail, dns, dhcp, authentication, and even telephone. It is my opinion and experience that, Linux will run these kinds of services better than Windows. The challenge of your post is the scope of your solution. Unfortunately, I can't think of a package or set of packages that you can simply install, run a few configuration. If you, and obviously in this case your entire team, are even somewhat new to Linux, you will have a mountain sized learning curve trying to implement a system of this magnitude.

One of the advantages of Linux is that it has both a community based support and organization as well as professional outfits. Probably the best known of the professionals would be Red Hat, a publicly traded company with a physical headquarters as well as a whole professional support network. I think that your best approach might be to contact them and see if they can put you in touch with a system integrator that could help you with a comprehensive solution and support package.

Bear in mind that this still gives you all the advantages of the open source systems: better performance, enhanced security (much less malware), solid community support, freedom from licensing restrictions (you don't have to pay for every user that accesses anything), enhanced visibility into the inner operations, ability to support multiple users simultaneously, improved networking tools, etc, while still offering the support network that a large company requires.

Noway2, thx for your response...

we know about the things which you are saying... we already started the testing with the applications available in Linux platform, like Zimbra, Citadel, Opengroupware, samba4, etc.

We already have a Fully linux Domain environment running in one of our site... here as it is a complete critical migration from MS backend to Linux, we would be happy to recieve any experienced hand's suggestions/comments/advice.... it will be helpful for us to reduce our investigation time...

We are in a similar, but smaller, boat, with 2 sites and looking at moving away from windows. We are getting close to the 75GB maximum for our SBS 2003 Exchange mail store size.

While I'm eagerly awaiting samba4 to emerge from being an alpha release, I think the first step for us will be to transition from exchange to another mail server, that links to LDAP for authentication.

Seeing as you are transitioning to a new domain name this seems like it will simplify the mail server transition as you can progressively set people up on the new domain name without affecting their old mailbox.

I read somewhere about samba4 alpha 12ish not supporting multiple site domains yet. Does anyone know if this has changed in the current versions? Reading through the alpha 13/14 stuff on http://wiki.samba.org/index.php/Samba4 again, I can't seem to find info on multiple sites apart from not renaming the default first site. My main concern with this is if workstations at one site randomly choose to use a DC at another site for authentication it will cause increased inter-site traffic and slow authentication for the users

A bit of good news for debian people using samba4 from the experimental tree that bind9 has been updated to 9.7.2 in experimental, which is supposed to allow AD integrated DNS auto updates to work according to http://wiki.samba.org/index.php/Samba4/HOWTO.