Disk Imaging Recovery Software with Copy-On-Write Snapshot Technology Lessens the Burden of “Digital Disasters”
By Don Lewis, FarStone Technology
When mishaps, malfunctions, failures and crashes take down a computer system, the potential for lost data and increased calls for Technical Support assistance can cause a “digital disaster” that affects both computer system builders and end users alike. For the system builder, warranty period obligations can lead to a high volume of tech support calls. For end users, PC configurations are always changing, as users constantly create and save new files and install or update software. Any changes that were not previously backed up are at risk for loss without a good back-up recovery system in place.
Common Digital Disasters
- Virus / malware attack
- Failed software / application update
- Accidental deletion or overwrite of saved file
- Operating system crash (aka the “Blue Screen of Death”)
- Hard drive failure
System builders can avoid the hassle associated with customer system crashes and potential data loss by designing a robust PC system that includes the provision for system utilities for continued self-maintenance and self reliance for the end user. Of all the necessary tools for a proper system, recovery tools are most essential, because system crashes have the potential to affect everyone, resulting in costly non-productive downtime and possible lost revenue for businesses.
Different Options for Back-up and Recovery
An effective back-up and recovery solution allows for the instant return to a previous state after discovering a system error or data loss. The goal is to minimize the recovery time it takes to get a system fully operational again. There are several different options for backup on the market today, but many do not offer the most complete and effective solution.
First, many businesses have commonly used the magnetic tape method, where all updated data is recorded to a cassette tape at the end of each day. This method makes recovering a downed system time-consuming and cumbersome, because the user has to locate the correct tape and then search through all of its contents to find the specific data to recover. In addition, the magnetic tape method does not guarantee accuracy because most businesses fail to test their recovery process prior to an actual system failure.
A second method, used by very small businesses as well as consumers, is to burn copies of important data files to other physical media. Again, this is a time-consuming, manual process, and it can be expensive to maintain the required media.
A third method is to use an online backup service. But with slow upload times to a central server, possible connectivity issues and the expense of paying a recurring fee, online backup does not present the most complete solution either.
A More Complete Solution
There is one major flaw to using the three methods described above: users are only able to backup their data. Just like the insurance industry talks about the “Principle of Indemnification” (to make whole again after an insurance claim), localized disk imaging with continuous data protection provides real-time recovery tools to restore a system to a complete operational configuration following a computer system crash.
The continuous data protection process is independent of the operating system, a pre-OS application, that includes the ability to make full image backups of a system coupled with instant snapshot updates (i.e. incremental backups, Figure A).
Figure A: Incremental Backups
The result is quick recovery from system crashes, file version tracking for recovery of one or more versions of the same file, scheduling functions to automate the process so it can become a “set and forget” application running in the background, a secure design that includes password protection to prevent backup or recovery operations by unauthorized users and the storage of all backups in a hidden and protected partition which cannot be accessed by viruses and malware, nor accidentally deleted by the user.
Snapshot technology provides real-time, continuous data protection. This block-level backup method is triggered by the hard drive’s current status. It only backs up changed (logical) sectors when a filter driver located beneath the file system identifies that an application is writing a sector-level change to the hard drive. This is monitored on a continual basis and recorded at each manual or scheduled snapshot that is taken of the hard disk. The requirements for storage space are small because only the changes are being stored.
The snapshots are made possible through Copy-On-Write technology. This basically means that a special filter driver monitors all sector-level changes to a system’s hard drive in real-time and stores the changes to a previous state (i.e. prior backup point) into a hidden protected partition (also known as a “virtual partition”) at the point a change is being written to the hard drive (Figure B). When a change is observed, a copy of the original sector data being changed gets copied and stored as well.
Figure B: Copy-On-Write Snapshots
At the point of a system malfunction or crash, the user selects a previous snapshot, and the software restores the original sector data. It compares the current state of the hard drive to that of the chosen snapshot. Like a time machine of sorts, the system is effectively rolled back to an earlier time. Because only the changes to the system and specific sectors are being “undone,” the time to recovery is very quick. This is the real added value when compared to the traditional backup methods mentioned above. With instant recovery comes minimized downtime.
The disk imaging software method that uses Copy-On-Write snapshot technology is a “win-win” solution for both system manufacturers and end users alike. For the system builder to implement this solution, it must provide for simple manufacturing integration onto existing production lines.
Even if full manufacturing line integration cannot be achieved, bundling after-market software with every PC that ships out is still a value-added activity that can save them and the end user a lot of headaches. For example, system builders who purchase Intel Desktop boards (945/955/965 chipsets) receive a CD with bundled software from FarStone Technology for this specific purpose: to provide a system recovery utility with every system.
Most importantly, snapshot technology solutions are easy to use and provide a variety of recovery options for end users, for example: (1) recovering from a full system crash or after replacing or upgrading a hard drive; (2) restoring a system one hour prior to the failed update of third-party software; (3) recovering a PowerPoint presentation that you “saved” when you actually meant to “save as;” thus overwriting the original file; and (4) restoring the system in a pre-OS (real-mode) environment because your Windows operating system won’t boot.
Disk imaging software with snapshot technology provides a simple, convenient solution for any system manufacturer and provides seamless protection for the end user. Users can rest assured that they will recover from computer system crashes without losing precious data if they implement of a solid and complete recovery software solution.
About the Author
Don is the Marketing Manager at FarStone Technology, Inc., a leading developer of PC and network-based recovery solutions based in Irvine, CA.