Data corruption usually happens at the worst possible time and when you least expect it. Data corruptions can happen as a result of any or all of the following five events:
1) Power failures or spikes;
2) Improper shutdown;
3) Network problems;
4) Hardware failure;
5) Human Error.
What does it take to avoid data corruption on your network? This article provides suggestions you can use to spot, prevent, or repair data corruption.
Implement a Backup Routine
A routine is the core of the backup procedure. A well-thought-out procedure prevents the corruption of data. The routine would include the method to create the backup. The routine would specify the frequency of the back up and specify a particular time for executing the backup. The routine would specify safety precautions such as writing data in the read-only mode to prevent accidental overwrites. The routine would also prescribe the verification and testing procedure after the backup has finished, The data needs to be verified to confirm it is intact and usable.
Media Should Drive Procedures
Even the highest quality media will cause some data corruption due to wear. Tapes and DVD are prone to experience wear and degradation over time. That's why it is good policy to establish how long data backups should be maintained, and system of multiple backup routines should be in place for more critical data. No single one piece of media should include large amounts of data. Distribute the data over several pieces of media. If corruption does occur on one of the media sets, an entire system will not be affected.
External hard drives can be connected locally to the network. The operating system has the capability to detect problems during the write process. If an area on the hard disk is not usable the system will mark it and continue with the next available space. Once the backup procedure has been completed, these external drives can be removed and stored securely.
The expense of hard drive media is a consideration. Using a combination of optical or magnetic media and external hard drives would be less expensive. The most critical data would be stored on the hard drives. Less-essential data would be stored on DVD or tape backup. A factor to consider when trying to prevent data storage corruption is time value of the data. It may be more cost-effective to lose a day or weeks' worth of less-essential data if the cost of a particular storage & media is greater than the value of the lost data.
When selecting storage media the cost and availability of the equipment reveals much about its quality and viability of using it as a long-term solution. Low cost media carries a greater potential for errors and instances of failure. If this is the chosen route for performing backups, then the backup image should be rigorously tested before new transactions are conducted. Again, it all boils down to how much risk a company is willing to endure in the case of corruption. Higher quality media does come with a higher price tag, but the advantages far outweigh the costs.
Don't Burn Your Bridges
When it becomes necessary to restore backup data, step one prior to beginning the restore is to create a system restore point to minimize damage in case data corruption occurs during the restore. If data errors do occur during an attempted restore from backup the restore point will roll back the system to the prior configuration before. Another option is to have software tools on hand to rebuild the image. There are restore applications that can reconstruct data that has been damaged. That's a subject for another article.
Have Recovery Software to Repair Corrupt Data
Recovery software can piece together segments of data to restore corrupted data provided enough data is readable. Some software uses parity bit data to reconstruct a corrupted sequence of data. Other software can restore missing bits and bytes of data by using a mathematical logarithm to determine the most likely value for the corrupt bit. Research your software options before needing them. Know what is available and know where to get it.
Verify and Test
Verify that the backup was successful. Test the restore procedure for proper operation. Test the integrity of the backed up data. Double check the integrity of the server data before going live. Check the system log files for any unusual activity. Spot check the data that was re-introduced to the system. If anything looks suspicious, follow-up and make sure that all hardware and software systems are operating as expected. Do not proceed with regular business activity until 100% confidence has been realized. One small error could result in wide scale corruption problems.
Article Source: http://EzineArticles.com/?expert=Terry_Mayfield
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