In-Depth
Imaging: Simple Data Protection in a Complex IT World
Adding an imaging solution to your data-protection strategy can protect you from any type of data or server calamity.
IT organizations manage a diverse set of transaction, communication, application, and database servers to support their application infrastructures. However, even the most complex deployments can benefit from some pragmatic and simple protection schemes. While companies typically have enterprise data-protection strategies in place, they often ignore the foundational servers themselves. When viruses attacks or a hardware failure cripples a computer, effective server protection can be the difference between a short hiccup in service and a weekend-long death march to reinstall and correctly reconfigure a key production machine. In the face of a catastrophic event, the tactical ability to bring up new servers quickly and efficiently provides a foundation for the overall recovery efforts. Organizations can use imaging technologies to protect and, when necessary, quickly and efficiently restore these servers.
Servers are as fallible as they are critical. The list of potential problems is long and often unmentioned due to our superstitions; power surges, disk failures, RAM failures, motherboard failures, widespread data corruption, and virus infectionsare among the problems that often take too long to diagnose, let alone fix. Even though your enterprise data may be protected, your servers are vulnerable, and downtime cannot be tolerated.
The Simple Benefits of Imaging
At its core, imaging is a simple technology. A disk image is essentially a snapshot, a reproduction of each sector of the drive; captured are the data on the drive, the operating system, partition records, and other critical system files it might contain. Administrators can protect servers and workstations, running Microsoft Windows 2003 Server, Linux, or any operating system with imaging solutions. An administrator can create an image from a healthy server and restore it to the same or different hardware to create a new, healthy server.
Using a data-protection solution to restore an entire server is like using a bulletproof vest where a life preserver is needed; it’s the wrong tool for the job. Unlike imaging solutions, most enterprise data-protection solutions copy the files on a given system, one-by-one, to an archive device where they are stored as a bundled collection of files. While these solutions are excellent at protecting and restoring critical data, they are poorly suited for restoring the underlying systems. Since they treat disks as a storage medium for files, data protection schemes don’t reliably handle critical records that are invisible to the operating system such as file system tables, file system journals, and master boot records. This problem is ideally solved by the disk image; simply copy the most recent image over to the server and reboot it.
Unfortunately, companies that don’t use imaging face the slow and daunting task of reinstalling the operating system and OS updates, all of the applications (including updates), critical settings, and the data. The process is tedious and prone to error. Administrators often struggle to find all of the system and application disks, track down all serial numbers, and find the drivers. This is a non-trivial, hair-raising trial with high stakes and eminent consequences.
Imaging is Better than Ever
Fortunately, administrators can deploy imaging software to fill the gap at a much lower cost than traditional enterprise-data-protection suites. Advanced functionality in imaging solutions provides several features that make life easier for the IT department daily and in the event of an emergency. While deploying your enterprise data-protection solution required a non-trivial investment of both time and manpower, not to mention the addition of several servers and the assistance of a team of consultants, imaging solutions can be installed in a matter of minutes on any server.
Imaging solutions evolved over the past few years and now offer many of the same scheduling features as data-protection solutions. Thus, administrators can schedule full, differential, and incremental images and can store their images on a wide variety of media, including network-accessible storage (hard disks and tape drives) of all kinds. Imaging software verifies images after they are created and before they are restored to ensure data and protection integrity. While data-protection solutions store backup files in bundles, images can be stored as single files. Thus, imaging solutions afford an ease of management that is sorely lacking in data-protection solutions.
These products are easy to deploy and manage, and they make efficient use of network and computing resources. Most imaging solutions have configurable CPU, hard disk, and network utilization so an administrator can image a server during normal hours without negatively affecting its performance.
Time-Saving Architecture
Some imaging solutions employ a simple console-agent architecture through which imaging agents can be pushed out to critical servers or workstations making the deployment task that much easier for administrators. The console-agent architecture provides a robust foundation for centralized management of disparate systems. The administrator of an imaging solution is afforded complete control of the solution from the central console, which provides them with facilities for distributing agents, monitoring systems, creating reports, and scheduling managing, cloning, restoring, and redeploying images.
All of this functionality provides administrators with a great deal of flexibility when they are faced with a serious problem on a critical server. This flexibility is just one of many attributes that make imaging solutions an excellent compliment to an existing data-protection system.
Protection and Recovery Scenarios
The best practice to protect both your enterprise’s data and its critical servers is to deploy an imaging solution in tandem with your enterprise-data-protection solution. In a typical scenario, an administrator might schedule full-image creation for each server on a weekly basis while building differential or incremental images daily throughout the week. The resulting level of protection provided by both the imaging solutions and the backup solution ensures that both server and data problems can be solved quickly with minimal loss of time and data.
Since images are treated as single files, they can be cloned and redeployed to other machines for redundancy or to create hot or cold spares. Administrators can use images to help them proactively prepare for failures.
In the event a serious problem occurs that requires a server restore, your imaging solution can resurrect the downed server in a matter of minutes. Administrators can restore a clean image back onto working hardware, restore an image on new hardware, or even restore an image onto different hardware. Imaging vendors include facilities to account for different hardware components requiring different software drivers so that the target restore platform can be different from the original server. Images can be tailored to fit on existing servers when applying the image to a new, bare-metal drive or server. This affords administrators flexibility in leveraging existing hardware in an emergency. Recovering from a failure, formerly greeted with a great deal of fear and loathing, is much easier when using an imaging solution.
Imaging technology itself is not universal. Each vendor employs its own methodology for disaster recovery. For example, some imaging software can restore an image to dissimilar hardware. One approach is to preserve the System Identification Number (SID) as well as all of the networking and domain information. This results in swift restores with all networking and domain information intact. Another approach is to strip out the SID and all networking information. This approach also allows the user to restore the system to dissimilar hardware, but then requires considerable manual reconfiguration in order to get the system back on the network. Any time you add manual interaction, you run the risk of adding user input errors.
Taking the earlier life-preserver analogy one step further, understanding the nuances of disk imaging can ensure that you select a backup and disaster recovery model that’s the right fit for your corporate environment. Ease of use, speed, and accurate recovery are the keys to any business continuity strategy.
Adding an imaging solution to your data-protection strategy can protect you from any type of data or server calamity, significantly increasing your chances of avoiding serious, time-consuming, high-profile, and costly service interruptions. In a disaster, you’ll turn confidently to this simple, effective approach to data protection.