Since the initial releases of OS X, Apple has developed a Server variant of the operating system, which has until now been a rather expensive option. With the end of the Xserve line and options like the Mac Mini server, Apple has made its Server software cheaper and cheaper, to the point where in OS X Lion it will be a $49 upgrade purchase from the Mac App Store. As a result some people may be wondering what OS X Server is all about and how it may benefit them.
MacFixIt reader "John" recently wrote in with such questions:
What is [OS X Server] for? What are the characteristics of the Mac user who would benefit from this? Why should I care? Looking at Apple's website, their writers take the approach that if you don't know what Server is for, then they are certainly not going to tell you. The writers jump straight into the weeds.
Take my situation. At home we have two MacBook Pros, an AirPort Extreme with disk and printer attached, iPhones and iPads. We use MobileMe for us and other family members. We have a top end iMac on order. Is Lion Server something we should consider putting on the iMac? How could we benefit? Based on Apple's website chicken scratchings, it looks like a solution to unknown problems, yet I can't help feeling that there may be something in there for us.
This is ultimately a simple yet tough question to answer, and the best way of looking at OS X Server is not that it solves some unknown problem, but rather that it provides new and enhanced functionality that may be useful to you, depending on your needs.
The standard OS X Client already comes with a number of "servers" that you can configure in basic ways. To see them, just go to the Sharing system preferences and you can see there are a Web server (Web Sharing), a file server (File Sharing), and a print server (Printer Sharing), among others, and these are by default configured to host simple sharing setups that are useful for most people. The difference between these and OS X Server is that OS X Server offers far more options for configuring and expanding these services, as well as providing others that are not included in OS X client.
For example, in OS X you already have the ability to "serve" Web pages by enabling Web Sharing in the Sharing system preferences. This enables a fully featured Web server (called Apache) but with a configuration that is easy to manage, and for the most part it just shows Web pages that you place in your Sites folder. In reality, however, the Apache program is much more dynamic and powerful, and can be configured to proxy Web sites, host multiple Web sites, offer numerous feature plug-ins, and handle a number of complex Web-related tasks that are not enabled in the client. OS X Server not only has Apache configured to better use these features, but provides interfaces for easily configuring and enabling them.
Do you need to host multiple Web sites on your system that interface with MySQL databases and run extensive PHP scripts? Do you need to set up a Web site proxy or WebDAV realms to allow users to write to locations on your server? Do you want to manage certificates so client systems can connect using properly established and secure HTTPS protocols? If so, then the basic Web server in OS X Client will not work and you will benefit from this aspect of OS X Server.
This is just one example and it may be irrelevant to some people, so to understand the scope of what OS X Server has to offer it is best to look at all of its services lumped into four general categories: Account Management, File Sharing, Network Administration, and Web Services.
User account management
This is perhaps the basis for a server, which is centralized authentication management that can be distributed to numerous devices and applied to various services. In some work environments, an IT department may set you up with a username and password that will not only work for checking your e-mail, but will also log you in to numerous computers, Web sites, and other items the workplace uses. This is the directory, which in OS X has been called Open Directory (Microsoft's version is Active Directory). This is where you create accounts that the server recognizes and uses for numerous other services it runs.
Beyond the directory itself are the domain management features of OS X, with which you can bind client Mac computers (such as your desktop iMac) to the server so the usernames and passwords in the server can be used to log in to the client Mac system. With this setup, you do not need to make new accounts on a system every time you want to allow someone to use a computer. Instead, you can go to the server and enable an account for a workstation, and that user can go log in to that system and use it. Additionally, if you purchase new systems all you need to do is bind them to the server and users can then log in to them with the same restrictions that they have on your other Macs (such as access only to certain applications, and only specific settings being available to them).
The next major features are the network services that are offered in OS X, which include the option to act as a router and firewall with the DHCP, NAT, and Firewall services, but in addition offer secured remote network tunneling to the server from the Internet with VPN services. In addition, it supports NetBoot options so you can start up any Mac the server manages to a boot image file stored on the server, which can be convenient for reinstalling OS X or running diagnostics. OS X server also has options for managing Wi-Fi hot spots with a RADIUS server, which allows you to lock down the Wi-Fi hot spots and manage passwords on a per-user basis. This means someone with an account on the server can connect to any Wi-Fi hot spot managed by the server by providing the username and password, instead of a single password being shared among many people.
File sharing and serving
Beyond network administration are file-sharing services, which allow for quick access to network shares and control what folders users have access to and how they can access them. OS X Client already has many of these features, and provides options to use standard OS X file sharing, Windows file sharing, or the older FTP protocol. While OS X Server does not have that many more options (namely, only NFS support), it does offer ways to customize these services, such as limiting the number of users, guest access, idle user management, and authentication requirements. File-sharing services branch out to other details like Time Machine and Spotlight services that OS X Server has, which can turn the server into a Time Capsule for network clients to use for backups, and also provide a central location for network clients to quickly search for files on other systems on the network.
The last major component of OS X Server is the Web services, which include the Apache Web server, as well as support options such as MySQL databases and PHP scripting languages for running Web applications, and Wiki Servers for establishing local how-to or information sites. In addition, OS X Server can offer centralized calendaring just like having your own Gmail or MobileMe calendar, an e-mail server for providing your own e-mail accounts to users, iChat services so you can log in to a more securely managed Instant Messaging option than using AOL's servers, and DNS options to customize the way systems resolve hostnames to IP addresses (an example of this would be to route network users to a specific server hosted by the company instead of to a public version of the server).
Those four categories are the major components of OS X Server, but there are others as well, which include QuickTime streaming for managing streaming media on Web sites, Podcast Producer for quickly creating and publishing podcasts, Xgrid for managing distributed processing in applications that support it, and Software Update for providing your network with customized distributions of OS updates.
Overall, OS X Server is the same OS X that everyone uses at home, but it has enhanced features and programs that allow for detailed connectivity options. There are a few features that home users may find useful. For one, having centralized user authentication and access for systems in the house might be convenient, especially if you have more than two computers with multiple people using them. Kids' accounts can be further restricted, similar to having parental controls set for all systems.
In addition, the ability to store files in a central location can be beneficial, especially if you have large storage requirements. Many people use NAS devices that serve the same purpose, but with a server on the network you can easily set up shared files and folders for iPhoto libraries, iTunes libraries, and options for quickly sharing a file or folder, and manage access through the centralized user accounts on the server. In addition, OS X Lion Server will offer file-sharing options for iOS devices so you can quickly create a document on one device and share it with other devices without having to use Apple's iCloud or e-mail it to yourself.
Finally, print services may be attractive to people who work on multiple machines and who manage multiple printers. While having one Mac set up to share printers is easy to do, you can set up the server to host all the printers so you can keep your other Macs asleep or shut down without putting your printers offline.
The real question for home users is whether or not to manage network services by themselves, or whether to subscribe to an online service such as Apple's iCloud. Many OS X Server features are redundant with options offered in devices like the AirPort Extreme Base Station (printer sharing, file sharing, and so on), so most home users will not have much need for OS X Server. Nevertheless, it is there and much more affordable if you wish to give it a try.
Do you use OS X Server and have recommendations for how you use it in a home environment? If so then let us know in the comments.