Mac OS X Server for Intel: Should You Make the Switch?
It took Apple only 10 months to go from announcing and shipping the first Intel Mac to completely switching its product line to Intel processors. Not only does Apple deserve credit for completing the transition faster than anyone expected, but also for doing it in a way that was almost seamless for most users. Mac users might have had to question the timing of buying a new computer, particularly creative professionals who rely on processor-intensive applications such as Photoshop that are not yet available in an Intel-native format. However, although there was a question of the performance of certain tools on Intel Macs, there was little question of whether or not the thing would ultimately work.
The transition is not so clear-cut for Mac server and systems administrators, however. As I wrote in an earlier article, because Mac OS X itself is not universal (that is, there are separate Power PC and Intel versions that are processor-specific), maintaining an organization that includes both Power PC and Intel Macs requires some extra effort and planning. Now that Apple is shipping a version of Mac OS X Server for Intel Macs and has released the first generation of Intel-based Xserves, the question is not only how and when to transition the Mac workstations in your network, but also how and when to transition your servers.
Implementing Mac OS X Server on Intel Macs can have different issues for different types of organizations and the type of transition that you are planning. If you are a small organization with only a few servers and you’re just adding a new file server, for example, the process will likely be no different whether you install a new Power PC or Intel server. If you are replacing an existing Power PC server that has suffered a serious hardware failure with an Intel server, you might have more issues because you won’t be able to simply boot from an alternate startup disk and use a backup utility to completely restore the server because although Mac OS X Server Install disks are now universal, the operating system itself is not. If you have a large number of existing servers and typically rely on NetBoot or a disk image deployment technique to rapidly and easily deploy new servers, you’ll need to plan for Intel servers separately from your existing Power PC servers.
Building a New Server vs. Installing Using a Disk Image or Backup
One of the biggest concerns to look at, particularly in enterprise situations that feature large numbers of servers, is how you configure and deploy your servers. Mac OS X Server offers a number of options for rolling out new servers, including the basic GUI install using the install disks from Apple; network-driven installation from the command line; auto-install and configuration using various forms configuration files; and disk image–based installation using technologies such as NetBoot, NetInstall, or Apple Software Restore (and the related GUI front ends available for ASR). In the event of replacing a pre-existing server (whether as a result of the server’s failure or just as an upgrade), you also have the option of doing a restore from a third-party backup tool.
For administrators that deal with large numbers of servers, it is often helpful to maintain a generic server disk image that contains basic configurations that could apply to almost any new server in the environment. This image could, for example, contain directory services roles and information as well as information for locating or providing network services such as firewall and DNS, or even basic file services information. By having the disk image ready when new servers are purchased, you can breeze past the actual install process and much of the configuration process, leaving only the need to configure things such as the server name and specific services or share points. If all data other than the operating system is stored on a separate volume (always a good approach for any server), you can even use this as an approach for replacing damaged servers quickly. Unfortunately, if you are planning to implement Intel servers, this approach will not be viable unless you also create Intel images. This means that if you plan to implement Intel servers along with Power PC servers, you need to actually build the server and then the image by going through the install process.
In most smaller organizations, a traditional server install is more often used for deploying a new server than a disk image approach. However, even this process can be streamlined. Apple’s Server Assistant enables you to create plist files containing server configuration for later use. You can do this when you first configure a server, once a server is set up, or you can even do it without having a configured server (in which case, you’ll need to describe the server configuration as if you were setting it up).
Saved configuration files made by using Server Assistant can be stored on any volume that the server has access to or in an Open Directory domain that the server will locate by default during the install process. You can even specify multiple server names for mass deployments. Although this is not quite the one-stop configuration option that a disk image is, it does enable you to automate much of the process, and it will work regardless of the platform.
If you want more detailed and granular control than is offered by Server Assistant, another option is to use Server Admin to store plist files for each service that you want to configure. Exporting each service’s settings in Server Admin is relatively simple: click the icon that resembles a calculator just above the save button in the service’s settings pane, which displays a thumbnail of the pane’s contents, and drag the icon to the desktop or a folder. The plist file can then be dragged into the same service pane on the same or a different server to apply that configuration. Although this involves touching each service that you need to configure, making it slower than a disk image and Server Assistant, this approach that works regardless of the server’s processor platform and it is faster and easier than manually configuring each service.
You might want to consider these approaches as an addition to your current backup plan even if you have no immediate plans to purchase a new server. If you have a server failure and are forced to purchase a new Intel server unexpectedly, having the requisite configuration files for each service and a separate backup of your Open Directory domain (as described in an earlier article), you’ll be able to get that server up and running faster than by manually configuring it. This is important given that you won’t be able to restore the Mac OS X Server operating system files (including service configuration and your Open Directory domain) from a Power PC server’s backup set to an Intel server (although in theory you could identify and restore some of the configuration files). You should be able to share any shared data or user files, however, without incident.