So-- Current situation: Two XServes. One G5 from 2005 (secondary), one Xeon from 2008 (primary). The primary server is an Open Directory master, serving around 125 users. 1TB of data storage, set up as a RAID 5. Only 50% or so capacity. A few web items too. The secondary server is the OD backup, and used for some small web services, which I could easily migrate to another server offsite as needed. It is also used as a Time Machine server for a few critical Macs. Our department (I'm at a University) is in the process of merging with another. I will eventually need to support around 225 users. Their total data storage is greater than ours; I will eventually be responsible for around 6-7TB of data, and need some room for expansion. The other department is currently using some old Windows servers, which I would like to retire. I would also like to take this time to replace my Apple servers, which are getting a bit long in the tooth. I'd also like to be able to join my new servers to our campus Active Directory, and allow users to log on with their campus authentication. So. Should I be looking at Mac Pro or Mac Mini? My current primary XServe, the workhorse, has a 2.8 gig Xeon processor, quad-core, and only 4GB of RAM. The only services turned on are OD, file serving, and web serving. It generaly reports as running at about 20-25% of CPU utilization. Of course, the new server will need to handle about twice the user load and around 6-8x the data storage. Budget wise, of course, the Mac Mini is tempting. I could buy two Minis, use one as primary file server and OD Master with a 12TB Thunderbolt promise RAID array (10TB usable), the second as secondary, OD Backup and for my web needs. I could get both of these for under six grand. They would fit easily on a shelf inside my existing server rack. Or, I could get one (or two) Mac Pros. From a horsepower standpoint, one Mac Pro could obviously do everything I need. But I kind of like the redundancy of having two Mac Minis, especially with them being OD replicas. If the primary were to crap out, I just switch the Promise RAID to the secondary, and life goes on. I welcome any thoughts on this, especially from those of you using Mini or Pro servers in a departmental / small business context.