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Recovering missing or corrupted files

Are you suddenly unable to read an important file from a hard disk, memory card, tape, or other medium? Backups do not exist, or do not work? Help is available.

Shut down the system

The surest way to prevent further damage is shutting down the system abruptly, such as by unplugging a desktop computer from the mains, or by removing the battery from a notebook computer. In normal usage, it is important to shut down the computer cleanly (such as through the Start menu in Microsoft® Windows®) so that the operating system can write information to disk. However, in the case of data loss, it is safer to avoid those writing operations.

In short: the less you try to operate a logically or physically damaged disk or other medium, the better. Also, making notes of what happened, as well as of your own actions, may prove useful should you need to consult a recovery specialist later on.

Types of damage

Logical errors

These problems are typically caused by careless use, or by defective or malicious software. The disk or other medium is physically undamaged, but one or more files cannot be found or opened. They may have been deleted entirely or in part, or the file table, allocation table, or similar metadata may contain an error.

Logical errors can often be repaired using special software tools, without having to e.g. open the casing of a hard disk drive. However, you should only use a quality tool that is designed for the type of situation at hand. Any failed attempts are likely to aggravate the problem, and may make recovery more expensive.

Physical damage

If the medium is physically damaged, such as by wear, impact, water, electricity or fire, software tools must not be used. At best, they will have no effect; at worst, they will aggravate the problem.

In the presence of physical media damage, recovery probably requires lifting the data off the damaged medium in a laboratory environment.

How to proceed

We partner with Ibas to provide you the absolute best in recovery service, from self-service software tools to advanced clean room techniques. Contact us, and we will help you decide on the most cost-efficient course of action.

Comparing costs

For your own use when weighing up your options, you should also estimate the costs involved with rebuilding as well as abandoning the data. Comparing these costs to those of recovery will help you make the right choices.

Rebuilding refers to work such as keyboard operators re-entering the information from paper documents. The costs of abandoning the data may include e.g. giving up receivables that cannot be charged due to a loss of invoicing data.

Prevention

An efficient backup strategy will minimize your likelihood of ever having to recover data from a damaged medium. Here are a few points to keep in mind:

• Backup media must be in perfect working condition.
• Backups should be created (or updated) at least daily.
• Restoration should be tested before an emergency arises.
• Some backups should be stored off site.

Also remember to keep your backups secure. Do not allow them to become an intruder's shortcut to the information in your data center. If you decide to encrypt your backups, be sure that the encryption does not prevent their intended use.