Rethink Clean Installs, Updates, and Reformatting Options for Lion Server
Because the OS X Lion Server installation process is so different, you may have to rethink preconceived notions about clean installs. Conventional wisdom has been that a clean install gets rid of the flotsam and jetsam of configuration files and old settings that accumulate over the years and slow things down.
With Lion, however, Apple encourages upgrade installations and has made it more difficult (though not impossible) to do a clean install by not providing bootable DVDs — or a way for you to make one (aside from unsupported hacks). The reason for Apple’s focus on upgrade installs may be a new generation of installer. Apple has indicated that Lion’s installer is smarter than previous installers.
Apple may be right. If you’re upgrading your current Mac OS X Server 10.6 to Lion Server, upgrading on the existing drive may be better than trying to migrate the server settings and data to a clean install of Lion Server using the migration assistant. This is particularly true if your old server is hosting websites or is using MySQL, which is no longer present in Lion.
You can still find good reasons to do a clean install, particularly if you’re not migrating an existing server. And the Lion Server installation process is actually easier if you’re installing onto a blank drive while booted from Mac OS X 10.6 or 10.7 Server.
It allows you to skip the step of having to go back to the App Store to download the server components, and it further automates configuration by invoking a server setup assistant that can do things like create an Open Directory master and configure DNS.
If you plan on erasing the drive, consider your storage formatting options before installing. You have three:
Use a simple erase.
Divide a drive into multiple partitions.
Use multiple drives together in a software RAID (redundant array of independent disks).