Mac OS X Server

Mac OS X Server (pronounced ‘OS ten’, not ‘OS ex’) is Apple’s new workgroup and Internet server operating system, and a precursor to the desktop Mac OS X, which is due later this year. With OS X Server Apple aims to consolidate its share of the traditional education and publishing markets, and to gain new customers in Web development.
OS X Server grew out of the ill-fated Rhapsody project, and features the preemptive multitasking and protected memory Included in Rhapsody and also promised in OS X. It is based on a Mach microkernel, which Apple says is the equivalent of Mach 2.5, and an implementation of BSD 4.4. (Perhaps this explains what the Apple developers ‘not officially’ working on MkLinux were actually doing — developing a stable Unix kernel for the PowerPC processor.) While it uses most of the POSIX APIs required for Unix systems, it is not fully POSIX compliant. and Apple is careful not to call OS X Server a Unix implementation.
Apple recently announced that parts of the operating system source code would be available free to developers. The open source version, dubbed Darwin, includes ‘enhancements’ to the microkernel and operating system, as well as key Apple technologies such as AppleTalk and the HFS Plus file system. Open Source Initiative co-founder Eric Raymond welcomed this release, but other open source gurus were less enthusiastic, concerned about Apple’s licensing agreement.
Apple is not proposing OS X Server as a replacement for AppleShare IP, at least not immediately. AppleShare IP has features OS X Server does not, such as mail servers, SMB support and firewalls. Apple is not discussing its plans regarding future releases of AppleShare IP, and says it intends to incorporate all the features of AppleShare IP into OS X Server, and eventually to phase out AppleShare IP.
OS X Server includes Version 1.3.4 of the Apache Web server, which was the latest version available when the OS was released. (At the time of writing, the latest
release of Apache is 1.3.6.) Because of US export regulations, Apple did not include SSL security libraries with Apache, but claims it should be fairly easy to implement Apache-SSL or other security plug-
ins. Also, given the alacrity with which security features were added to Netscape’s Mozilla source code, it is likely that the open source community will jump in to add security features to the OS.
The OS also comes with WebObjects 4, Apple’s own application server, which was previously available only on Windows NT and Unix. WebObjects allows you to build network applications that connect to multiple databases, and can dynamically generate HTML and Java. The version bundled with OS X Server is limited to 50 transactions per minute, which Apple says is sufficient for most small-to-medium-size workgroups.
Apple’s NetBoot feature allows networked iMacs and G3s to boot and launch applications from a central disk image on the server. Unless the server is heavily loaded, the OS and applications actually boot faster off 100Mbps Ethernet than they do off the iMac’s hard disk drive. In an informal demo, a G3 server running OS X Server booted an iMac and a G3 system simultaneously without cracking 5% processor usage.
NetBoot allows network administrators to set different levels of user access, and then to assign these levels to different users. This not only controls which applications, folders and resources can
be used, but can also change the user’s desktop interface from a full Mac OS interface to a series of point-and-click panels. Each user’s desktop, preferences and application settings are kept on the
server. This is similar to Microsoft’s Zero Administration Kit for Windows, but OS X Server works on the principle of one centralised disk image, rather than pushing settings and software upgrades to each client PC. The advantage of Apple’s system is that when it’s time to upgrade the software, only the central image needs to be changed, and the clients will automatically be updated once they reboot. OS X Server allows you to make these changes live without rebooting the server.
Finally, Mac OS X server includes the Apple File Protocol, which allows it to share HFS Plus disks with any Apple-Share client via TCP/IP or AppleTalk. There is no native support for SMB file sharing with Windows systems, but Apple is banking on third-party solutions such as Samba (see page 40) becoming available. A full range of administration functions can be performed remotely, using the Remote Administration tool through any Web browser over your network or the Web. Access to this remote administration can be secured using Kerberos user authentication, but subsequent information is sent to the Web browser as clear text.
Mac OS X Server only runs on Apple G3 server systems, and is available for $795, or $ 10,995 bundled on a G3 server.