Offsite service or software: Which continuous data protection solution is right for you?
Protecting your data is crucial, and there's no shortage of products available to help you do so. You've probably heard a lot recently about continuous data protection (CDP) products-solutions that use software, hardware, services, or any combination thereof to continuously back up data to disk locally or remotely and restore data from any point in time. The CDP space is burgeoning with a wide range of products and price tags, ranging from sub-$500 standalone single-disk-based hardware systems designed to protect a desktop to full-scale data-replication systems to seven-figure SANs. If you're thinking about buying a CDP solution, the two products I look at here, LiveVault InSync and NSI Software's Double-Take—though they represent completely different CDP technologies and in many ways are at opposite ends of the CDP spectrum—will give you an idea of what CDP technology does and where such products might fit in your organization's data-protection scheme.
The biggest data-protection issue in the small-to-midsized business (SMB) world is ensuring that data is backed up regularly in a reliable, safe, and secure fashion. Smaller businesses are parsimonious about the resources they can dedicate to IT, and their IT staffs often find themselves fighting fires with little time to devote to important, though routine, chores such as backing up the server regularly.
The LiveVault InSync online backup and recovery service is made for such environments and is the closest thing I've seen to a true "fire-and-forget" solution for data protection. LiveVault InSync backs up selected data directly to offsite storage via the Internet. The service uses a small server agent and a simple Web-based interface to configure, back up, and restore data from any protected server (Windows Server 2003, Windows 2000, Sun Microsystems' Solaris, or Linux). LiveVault InSync's only real limitation is that the amount of data you can protect is constrained by the network bandwidth of your Internet connection. Both upstream and downstream data rates affect the efficiency of data backup and restore. LiveVault provides guidelines about the amount of data that you can effectively protect given your bandwidth-connection speed.
Setting up LiveVault InSync's data protection couldn't have been much simpler. I logged on to my account on the LiveVault InSync Web server (LiveVault sets up the account after you purchase the service), clicked the New Computer icon, and downloaded the LiveVault InSync agent for Windows 2003. I then installed the agent on the local Windows servers I wanted to protect, a task that took only a few minutes per server, with the bulk of that time spent generating a unique encryption key for each server. I rebooted the servers, which were now ready for me to add to the LiveVault InSync CDP routine.
To do so, I logged back on to the LiveVault InSync Web server, configured a backup policy for each protected server, and saved the policy, which automatically initiated the backup. To recover data, I simply opened the Web console and selected which files I wanted to restore to the server; the LiveVault InSync software agent maintains the necessary connection to the offsite storage servers for both backup and restore. I restored a directory tree containing four folders with 139 files totaling 513MB. LiveVault InSync provides several screens, such as the one that Figure 1 shows, that let you view data related to backups and restores as well as run reports and set backup properties. In addition to restoring Windows file-system files, LiveVault can restore Exchange mailbox stores and the Public Folder store, although it can't restore individual databases.
LiveVault InSync is a good solution for SMBs that need to provide CDP for a subset of their complete business data. The service's ease of use and minimal support requirements make it ideal for organizations that lack comprehensive IT support.
NSI Software's Double-Take CDP software is amazingly simple to get up and running, especially when you consider the benefits it offers your computing environment in terms of security, availability, and data protection. Double-Take provides real-time byte-level data replication and support for point-in-time recovery (where you can restore not only the most recent replicated data but data from a specific historical point). These capabilities let Double-Take offer significant data-recovery flexibility to IT departments at SMBs and larger enterprises. Double-Take runs on various Windows OSs, including Windows 2003, Windows 2000 Server, Win2K, and Windows NT 4.0. Its disk-space requirements depend on the amount of data you want to replicate.
Using Double-Take's wizard-driven installation, I installed the software on two servers and set up a data-replication configuration in about 30 minutes. (Double-Take doesn't require the server pairs involved in the replication to be matched.) More complex tasks, such as configuring data protection and failover for applications such as Exchange or Microsoft SQL Server will take a bit longer, although Double-Take provides a wizard for setting up the CDP software for Exchange (the product supports Exchange Server 2003 and Exchange 2000 Server) and a detailed application note containing guidelines for setting up protection for SQL Server.
You manage Double-Take through a Microsoft Management Console (MMC) snap-in, which Figure 2 shows, that gives you a consistent UI for all Double-Take tasks. For my testing, I set up a simple mirror across two servers of a 1GB data set that I configured to change fairly quickly, with roughly 10 percent of the data being modified every 10 minutes. Double-Take had no problem keeping up with that high a rate of data change on the servers connected over my LAN. To simulate a WAN connection, I told Double-Take that the two servers were connected over a T1 connection and that the software could use no more than 50 percent of the connection speed. I then configured my test to change roughly 1 percent of the data set every 10 minutes. I monitored the replication process from the management console and saw that Double-Take had no problems moving the data and throttling its bandwidth usage as I'd requested. Double-Take's WAN data-replication feature also provides data compression.
Double-Take offers a number of features that make it a worthy candidate for any IT department considering a complete CDP or high-availability solution. The product provides detailed data replication, supports major applications, allows for complete server and application failover, and provides an intuitive and simple-to-use interface. For companies that need to replicate data across a wide variety of environments, support Microsoft cluster environments, or have significant storage-replication needs, Double-Take is an excellent value.