1) A lot of my customers use joomla, but in my new server running Virtualmin Pro, they cannot change any file in the Administrator area (file permissions). I read in a few tickets to chmod all files and folder to 777 but I really dont think that it is a good idea. Is there anything else that I could do about that?
That won’t work. Suexec won’t run anything 777. You need 750 or less.
The files need to be owned by the domain owner, as well–which means they’ll be able to edit them. If you were running them before owned by Apache, just think of this as an opportunity to absolve yourself of guilt and take a more righteous path.
2) I am getting the follow error message using postgre:
psql: FATAL: Ident authentication failed for user "postgres"
I’m not sure on this one–your scripts ought not be trying to use ident for authentication–they ought to have a username and password. I’d be happy to drop in and take a look, though, if you aren’t sure what to do with that.
3) How can I set my customers domain/website to send their emails with their own domain instead of contact@hostname?
I don’t know what you’re asking here. The client generally sets the From: field, but if yours doesn’t you can turn on the Canonical maps automatic setup feature in Virtual to create a map that’ll turn email@example.com into firstname.lastname@example.org (or similar).
4) Is it possible to install just once: squirrel / phpmyadmin / pgmyadmin, and from that instalation all my customers could access their respective informations (email/database)?
Yes. Both of those tools authenticate using the real username, by default, and don’t care what virtual server they’re attached to. SquirrelMail is also installed, by default, with the virtual users plugin, so you can (I think–I haven’t actually used it) set it up as an alias for all of your domains and allow users to login with their “friendly” username.
However, I’ll take this opportunity to point out that Virtualmin includes Usermin, a more powerful webmail client (browse to port 20000), and the Webmin MySQL module, a more powerful MySQL database administration tool. Both are aware of Virtualmin and Webmin configuration and settings and can be quite smart about how they handle users.
5) Where is stored the dns zone for my virtual servers ? I looked at the Bind section, but I can't see anything... and... If I try to insert manually, I get an error message saying that the zone what I am trying to insert already exist.
If you browse to Webmin:Servers:BIND DNS Server, while logged in as root (or a sudo capable user on Ubuntu), you should see all of the details of your zones. They are stored in different locations depending on users, but the rabbit hole generally starts in /etc/named.conf. We use OS standard packages and conventions in nearly every regard…so we store zones wherever your OS usually stores them.
6) Another thing about Bind is... all my virtual servers created isn't set correctly... if I check dnsreport.com or pingability.com I get a lot of errors like:
The primary name server per the SOA record (mydomain.net) on ns1.mydomain.net is not an authoritive server for this domain
Then you should configure it correctly.
Your registrar and your DNS server records should agree about who the authoritative server for your zones is. We don’t control or impose any limits on either one–but we do take a wild stab at what the value ought to be during installation of Virtualmin.
You can set it in the BIND Name Server module, in the Zone Defaults page, with the option labeled "Default nameserver for master domains".
Hope this helps.