Server Testing before Production

My wife's job as a technology coordinator is a tough one to be sure. There is never enough time for all the big tasks let alone the minutia. Since I am a "tech guy", I find helping out to be a value to both of us. One of the tasks that my wife gladly allows me to do is that of dealing with studying, planning, preparing and implementing server upgrades. Her organization is going to be implementing a 1:1 laptop program, and with the infrastructure improvements, we need to upgrade server operating systems.

Snow Leopard Server (10.6.x) has served the organization for almost 3 years in admirable fashion. Now that OS X Lion Server is at 10 months of age as of this writing, it is battle tested and patched to the point where it is safe to move the servers to the new OS. However, we never do anything without considerable research and planning. Not only are those steps important, but testing is a key element that so many people avoid.

Today, I am following the following test plan to see how the Snow Leopard to Lion Server upgrade will work on a test Mac Mini. In the first step, I have secured a Mac Mini similar to the actual production server. Both are Mac Mini boxes with Dual Core processors of the same speed. They do vary in the amount of RAM installed (4GB in production versus 2GB in test), however that is the only real difference.

The second step is to get an image from the production server without bringing the machine down for a prolonged period of time. The program I use is called SuperDuper and this program has proven itself over many times. It will repair permissions, then build an image of the production server hard drive to an external device in the form of a disk image. SuperDuper will also preserve the ACL (access control lists) of the production server.

The third step is to take that disk image of the production server's hard drive and image it back to the test server. I have my disk image on an external hard drive that connects via FireWire 800. Boot the Mac Mini test server from DVD or USB key and launch Disk Utility. Then use the "Restore" operation to take the disk image to the text server's hard drive. In my scenario this took about 30 minutes of time since the disk image from the production server contained no data share points. As a note, we always try to keep the data share points off the OS X Server operation system volume.

Once the test server has an identical OS X Server install to the production server, we can begin the process of upgrading the test server to Lion Server. I will not document that process here. The important issue to remember is that you are being safe in testing out whether the upgrade will work prior to committing to the upgrade in a production server environment.

A side benefit is the knowledge that your backup will work should the upgrade fail. On some upgrades, I have been known to do two backup disk images. Taking the server off-line and using Disk Image or SuperDuper are both good methods. While I have not tried Time Machine, it is my understanding that works for OS X Server migrations. In summer 2011, Apple server gurus favored doing the upgrade process over the migration process, which had bugs. Your mileage my vary now that OS X Lion is more mature.

Happy server upgrade paths to you.