I admin an ISP (relatively small operation but may scale exponentially in the near future). I recently moved to a vpop solution for our hosting customers and it's working great. We use qmail, courier-imap, qmailadmin, and HORDE/IMP for webmail. All existing domains were moved to the new server relatively easy. Only one left is our "main" company domain with a few thousand users and their personal webspace (a real gotcha).
CURRENT: We manage the "main" domain users with a custom program that parses the command line and runs the appropriate scripts to create the users in our own way (fancy way to create system accounts). Since these users are dialup customers too the scripting sends off the account info to our RADIUS servers (updates a cdb file) when we add a user. Problem is, the way it was built a long time ago required us to use system accounts to accommodate the "personal webspace" (FTP) we provide as well.
I want to make more of a vanilla setup (within reason) so I can find more
support options and allow more technicians to administer our services. I
like what I read about the flexibility of vpopmail with mysql as a backend.
But a few questions puzzle me...
1. Are there any drawbacks to using the mysql backend compared to using the
default vpopmail way?
I thought mysql was the default ;-)
2. Our "main" domain has few thousand mailbox accounts (which will grow). Will this present a problem to qmailadmin or with administration by our technical support staff (vqadmin)? Are there limitation that eclipse performance at some point?
I can't comment on this one, but I think I've heard that one can run several hundret thousand users via one mysql-server and have replicated frontend-servers with mysql-slaves on them.
Will probably depend on your storage-subsystem, the network and the usage-pattern of those users.
I assume disk-I/O will be a big problem at a certain point (concurrent users...).
Real world figures welcome ;-)
3. Anyone have input on a "virtual user" FTP solution for these customers, I've considered a separate server, vsftpd (but it requires a common shared dir) and the dreaded system accounts once again.
I've recently toyed with the idea to use davenport: http://davenport.sourceforge.net/ together with samba and mysql as a backend: http://www.freebsddiary.org/samba-pam.php I think it would be dead-cool, but I haven't found time to try it out.
Only problem is, you need either Windoze 2000/XP or KDE 3.x (OSX works, too, though) to use webdav natively.
Win95-NT4 need not apply... ;-)
5. Anyone have suggestions/experience with a giant NAS type setup where qmail/courier-imap/vpopmail would connect to for the user MailDir's? ...LDAP? ...NFS? I mean Hotmail and yahoo must have terabytes of attached storage they store
If you have the money, go for Netapp Filers: http://www.netapp.com (but you won't find pricing there...). Most expensive on the planet.
Else, I'd use FreeBSD as NFS-server. I don't know how well IDE-RAIDs scale in this scenario (lot's of small files).
Or Solaris x86 (Slowlaris).
And as I said, you have one mysql-server, one NFS-server as backend. the frontend-servers provide webmail,smtp, imap and mount the nfs-exported maildirs. They also have a read-only copy of the mysql-db.
And you might need some kind of load-balancing solution to map www1, www2, www3, ... to www....
their mailboxes on right? Any ISP's listening?
As you can see I'm stepping into some land I don't know much about but I'm
learning fast and willing to take the time to do it right the first time.
I'm willing to spend some time with a consultant for suggestions or just
plain real-world ISP type tips since I'm sure there are many variables.
That's the "real" experts ;-)