I'm running a network with 3 Linux servers and about 50 users and I'm looking into ZCS as a groupware product.

The current setup has:
* OpenLDAP as central account DB (for samba, mailserver, RADIUS, intranet, ...)
* Samba as fileserver, printerserver, PDC
* Sendmail with Spam and Virus filters, distributed on two servers (external mail-relay, internal mail server)
* Cyrus IMAP server with shared folders, various sieve filter scripts, ...
* Project-based mail-addresses with direct delivery into sub-mailboxes
* Currently about 120GB of mails in the Cyrus DB
* Web-based administration software (GOsa)
* PostgreSQL database
* OpenGroupware
* Apache for several intranet web applications

I'm now asking myself how ZCS would fit into this setup. It looks like ZCS brings it's own LDAP server and directory structure, has it's own MTA and mail database etc. so I would have to kill OpenLDAP, Cyrus IMAP, and all the setup, configuration and utilities grown in the past couple of years. Am I correct?

How intrusive would ZCS then be? What about the user account data (including Samba MTA) in the LDAP database? What about the directory structure itself (where the samba configuration depends on, for instance)?
What about the Sieve filter scripts and special mail delivery configurations?
What about addresses, calendar, projects and tasks currently stored in the OpenGroupware database?

So these are a lot of questions I'm currently thinking about and I don't know if I'd like the answers.

Has anyone already accomplished a similar transition?
I'm new to ZCS and as you can see from the setup above I'm rather "old-scool" and used to modular, separate servers like Sendmail, Cyrus IMAP server, OpenLDAP, Apache, etc.
Any comments from people who have done such a migration are appreciated!


- andreas