One of the reasons people purchase networked storage is for backup. NAS vendors have tried to meet this need primarily by bundling in a backup application. But installation and setup is left for the user to figure out and isn't required to get the NAS up and running.
The MSS also takes the application-level approach to backup, but makes it a mandatory part of the MSS software installation process. Backup is done by a combination of a program that is part of the WHS Connector that runs on each Windows computer and a service running in the MSS. Backup configuration is done via the Backup tab in the Windows Home Server Settings (Figure 22).
Figure 22: Backup configuration
The backup process takes a different approach from most backup utilities in that it works at the filesystem cluster level. Here's an edited excerpt from a WHS Forum post that explains:
Unlike most backup products that operate at the file level, the Windows Home Server computer backup solution works on "clusters". Clusters are the lower level constructs of the file system. They are usually 4k bytes in size on most NTFS disks.
The Windows Home Server makes sure that any particular cluster is stored only once on the server...even if that cluster is found on multiple disks and within multiple files. This is known as "single instance storage".
The first backup of each computer usually takes quite awhile, but subsequent backups go more quickly, depending on how much has changed since the last backup. Backup restores can be done on an entire drive image, or individual files or folders.
While I appreciate HP and Microsoft's efforts to make backup a regular event, the implementation has room for improvement. My main beef is that you can schedule only a single period during which only Windows machines that are running the WHS Connector will be backed up. You can always invoke a manual backup using the "Backup Now" option in the WHS Tray application. But that's not automatic, is it?
Since I don't like redoing even a small amount of work if I can help it, my current NAS is set to automatically back up my work folders every four hours during the workday. This approach is certainly overkill for the MSS' target audience of home users, but not unusual for home businesses and telecommuters. I should note that my backup is server-initiated and doesn't require an application running on my computers—an approach I definitely prefer.
My bigger problem is the backup feature's refusal to back up a volume that has any errors. One of my Win XP machines, which runs perfectly fine, threw the error message in Figure 23 during its backup, despite my following its advice to run chkdsk /f /r multiple times.
Figure 23: Backup configuration
The need for a "perfect" drive probably stems from the cluster-level backup approach. But if the problem drive is about to die (it's still running fine, thanks), I sure as hell would like it to be backed up...perfect or not! I also found the instruction to run something from the command line to be an interesting approach for a product that is designed for non-geeks.
If you miss the error pop-up or want more details on how a backup went, you can access the Backup Details screen via the Console Computers & Backup tab, View Backups (Figure 24).
Figure 24: Backup details
Note that backup will not work remotely (even if you're connected via the Remote Access feature) or if your computers are local, but on a different subnet.