Introduction
Arguably one of the most epic accomplishments of the 21st century was the invention of the computer and the subsequent creation of computer networks. These two entities have virtually transformed the world as far as information processing and communication is concerned. Although computers are hardly a century old, they have revolutionalized the way in which we carry out our day-to-day activities and hardly any arena in our lives has escaped the influence of these systems. As such, a breakdown of the computer systems would be catastrophic to an individual or an organization. Despite this, Goldsborough (2004) notes that a constant reality when working with computers is that the data stored on the PC can disappear in an instant. For this reason, it is of uttermost importance to ensure that contingencies are taken in the event that a computer system should fail. Crash recovery measures provide the best way to salvage a failed system. This paper will engage in a detailed analysis of how to carry out a crash recovery.
Computer Crashes
All computing systems are vulnerable to a wide variety of potential threats including; viruses, hacking, bugs, and physical damage to name but a few. All these threats may result in a system crash with varying consequences to the users. Bobrowski (2006) defines a crash as “the unanticipated failure of the system in question”. Crashes result in the computer system being inoperable until a solution to the crash is arrived at. There exist two major forms of crashes; hard disk crashes and OS crashes, and the recovery process will be dependent on the unique nature of the crash.
Hard Drive Crash
A hard disk crash is brought about from a hardware failure on the disk. A hard disk crash implies that all or some of the hard disk sectors are damaged and therefore unreadable. Hard disk failure may be caused by contaminants on the disk which may cause a head crash that damages some of the data on the disk. Head crashes may also arise from the hard disk being jarred while it is in use. Some of the signs of a hard disk failure are clicking or whirring sounds from the hard disk when the computer is turned on. To recover from a hard disk crash, one will be forced to invest in a new hard drive. Even so, one may wish to salvage the data that exists in the damaged drive.
Operating System Crashes
OS crashes are logical failures that make either part of or the entire OS unusable. In the event of a logical failure, the hard drive is still fully functional and the error is only on the OS. An improper shutdown of the computer due to power failure or poorly written software may damage critical system files resulting in an OS crash (Gookin, 2009). OS crashes may also occur as a result of memory overflow where data from one area of memory goes to memory allocated for another program. This may result in data corruption and the eventual crash of the OS. OS crashes can also be caused by viruses, which are malicious scripts written to interfere with the normal operation of the computer.
Crash Recovery
In the event of a crash, the first step is to identify the type of crash and then determine the best way to recover from the crash. For an OS crash, the primary goal of recovery is to get the OS up and running. This can be done by reinstalling the OS from the original disk. Most OS providers provide users with recovery disks which are very useful in the recovery process since they enable one to return the computer to its factory settings (Gookin, 2009). For hard disk crashes, the aim of recovery is to retrieve data from the damaged drive. One can use data recovery software to try and recover some of the data from the damaged drive. Recovery software is designed to access sectors of the hard drive that are damaged or retrieve information that may have been deleted in the event of the crash. While there is no guarantee that all the data will be recovered from the damaged hard disk, data recovery software present the best means to retrieve at least some of the data that would otherwise be irretrievable from the faulty hard disk.
Backing Up
Arguably the most important safeguard against computer crashes is backing up of data. Failure to back up important data may prove to be catastrophic in the instances where vital data is lost following a crash. Backing up is based on the premise that preparations must be made beforehand for the physical loss of an important OS file due to operation error, file corruption, or a disk failure. In this kind of disaster, it is impossible to recover the data from the system by the use of recovery programs. Backup copies of the lost data files are the only means through which the recovery process can be done. Backup software can be used to restore data from backups to a computer that has crashed. This is because backup software has modules for restoring files. However, this is only possible if one has already installed the backup software on the computer. In case the hard drive crashes, it is necessary to reinstall the backup software before commencing the recovery process. When performing backups, it is important to ensure that the integrity of the files is not compromised. Data integrity can be compromised by viruses which can damage files to the point that a computer cannot access the data contained therein. It is therefore important to ensure that files that are backed up are virus-free. This can be done by performing an up-to-date virus check as the first step in every backup routine (Parons & Oja, 2010).
Crash recovery can be assisted by the use of extra disks on the computer system. This can be implemented through the use of Redundant Arrays of Independent Disks (RAID) technology which is hailed as the fastest means to recover from a system crash (Goldsborough, 2004). RAID can enable one to replace their failed hard drive almost seamlessly. This is made possible since RAID mirrors all the data that one store on their main hard drive onto a secondary hard drive. Despite the huge reliability that RAID technology offers through redundancy, it is not commonplace among individual PC owners owing to the additional costs that RAID technology demands.
Identifying Crash Cause
An important step in crash recovery is to try and identify the cause of the crash. This is very important since it is desirable to avoid future crashes. There are commercially available software tools that can be used to diagnose the system for physical or logical errors (Miller, 2007). Having identified this, appropriate measures can be taken to ensure that future crashes are avoided. Scan disk utilities can help identify faulty hard drives by providing information on bad physical sectors. One can therefore take up appropriate action and avoid future crashes.
Conclusion
As our society becomes increasingly dependent on information technology for a myriad of operations, the responsibility to maintain and protect computing systems increases proportionately (Kilbridge, 2003). This is because, with the increased use of computers, the cost of system failure becomes significantly higher. There are instances where the cost of a system crash may be too high and in such a scenario, avoiding the crash completely is desirable. Running software tools that warn the user of impending problems is an effective way of subverting a disaster that may arise from disk failure. Third-party software utilities such as Symantec’s Systemworks have tools for monitoring the internal diagnostic capabilities of new hard drives to give an alarm in case of looming problems (Goldsborough, 2004).
This paper set out to discuss crash recovery measures that can be used to salvage a failed system. This paper began by noting that all computer systems are susceptible to crashing which may result in dire consequences for the person(s) who depend on the computer’s data. It has also been noted that crash recovery procedures will vary depending on whether the crash is an OS crash or a hard disk crash. In either case, the best way to recover from a crash is to take up proactive measures such as backing up all the data on a secondary storage device. This paper has also noted that the use of the redundancy capabilities provided by RAID technology presents the best way to recover from hard disk failure. Successful crash recovery will restore the system to its pre-crash status hence enabling the individual(s) to continue reaping the advantages of his computer system.
References
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Goldsborough, R. (2004). Signs of an impending hard disk crash. Teacher Librarian, 14811782, Vol. 31, Issue 3.
Gookin, D. (2009). Troubleshooting and Maintaining Your PC All-in-One Desk Reference for Dummies. NY: For Dummies.
Kilbridge, P. (2003). Computer Crash: Lessons from a System Failure. New England Journal of Medicine, 00284793, 2003, Vol. 348, Issue 10.
Miller, M. (2007). Beginner’s Guide to Computer Basics. Que Publishing.
Parsons, J.J. & OJa, D. (2010). New Perspectives on Computer Concepts 2011. Cengage Learning.