Installation of both the hardware and client software was basic. Plug in a network cable and the power supply, and it turns on and boots up. Bootup takes about 75 seconds, about what you'd expect for loading a more complete OS than a typical NAS.
To get the CDP working on your LAN, you'll use SonicWALL’s secure web based configuration utility (Figure 4). The CDP requires a static IP (default = 192.168.168.169); there isn't an option for DHCP. If your LAN is using a different subnet than the 192.168.168.0 /24 network, you'll need to use the supplied crossover cable to reconfigure the CDP's IP address, gateway, and DNS settings.
Figure 4: Network configuration for the CDP
Other than configuring network settings and changing the default password, there is little need for the CDP web utility. The remaining functionality comes from using the CDP software, which you download from SonicWALL’s website once you've set up a user account and registered your device's serial number and authorization codes.
Installation of the software is as simple as any other Windows package: just click your way through the screens to complete the installation. I installed the software on four different Windows XP machines and one Windows Vista machine without issue.
Two applications are loaded in the installation process: the Agent Tool and the Enterprise Manager. The Enterprise Manager is automatically loaded with the Agent Tool, but requires the CDP's password you configured in the web tool, which should keep inquisitive end users out as long as you use secure password management practices.
Once you complete the installation, simply launch the SonicWALL CDP Agent Tool to ensure it can access the CDP (Figure 5). PCs on the same subnet as the CDP will auto-detect the device. Two PCs on my network are on a different subnet, so I entered the IP address of the CDP into the Agent Tool's manual configuration option screen, which enabled access.
Once the Agent Tool sees the CDP, it automatically starts the process of continuous data protection by running a full backup of the contents of the Windows Desktop, Favorites, and My Documents folders.
Figure 5: The CDP Agent Tool
Additional folders can be added to the automatic CDP protection scheme by clicking the Add Folder icon and selecting the appropriate folder. Note: only folders on local drives can be added; trying to add a folder on a network or USB drive will result in a message stating, “Removable media drives and network paths cannot be selected.”
This initial full backup process may throw some load on your network if end users have a lot of files in the selected directories. This highlights one downside to continuous data protection: you can't control when it runs.
I'd recommend installing the SonicWALL software on client PCs after the close of business to minimize impact on your LAN. Once this initial full backup is complete, the CDP only sends block-level file updates as they occur, reducing load on the network significantly.
The workhorse of the CDP software is the application that runs in the background on each PC and Server, watching for disk write activity to the defined directories. Using Windows Task Manager as in Figure 6, you can see the CDPAgentService.exe application is only using 1% of my laptop's CPU, and this was while saving a file to a folder configured for monitoring by the Agent Tool. I talked to the product manager at SonicWALL, and he told me the Agent software monitors the CPU utilization on the host PC and waits for low CPU utilization before pushing updates to the CDP.