A Brilliant File Verification tool: A Second Opinion For Your Data’s Integrity


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A brilliant file verification tool gives you a second opinion for your data’s integrity

All of us copy files from time to time, whether that is just moving some valuable documents to a thumb drive, backing up some folders from one hard drive to another, or using a synchronization program to make duplicates of important data.  Many of us have probably also experienced the gut-wrenching feeling when we discover that those copies which we were depending on turn out to be damaged or corrupted in some way and are unusable.

ExactFileMany file backup and folder synchronization programs perform some sort of file verification on their own.  Still from time to time I have seen where even that has failed because of a bug or another glitch. When you simply copy files using Windows Explorer, cycle redundancy checks (CRC) are performed on files to help insure copy integrity, yet occasionally you still end up with corrupt files on the other end.

To avoid such problems, special tools have been developed to do more thorough checks in order to confirm the consistency of files.  Most of these tools employ various checksum or hash check methods to examine the contents of each file for discrepancies.  Every file has an unique checksum so if the file is changed in the slightest way it will be detected.

This technique has been commonly used to make sure files downloaded from the Internet are complete and unchanged in any way.  If you have ever seen a string of numbers called a MD5 or SHA1 sum listed next to a file download that is what those are there for.  This same technique can also be used to verify that the files you copy from one location to another are complete and unchanged.

ExactFile is the only free checksum utility I have found that includes a feature which makes it truly easy to do hash checks on large sets of files.

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I'm looking for something that uses better algorithms; MD5 is real slow.

thanks very much - i will give Teracopy a try.

I copied some very large files from one drive to another last night - had a hardware problem that corrupted at least some of them, I'm afraid. today I'm using Nirsoft HashMyfiles to generate hashes for both the source and destination files. It's very slow, apparently now reading only about 25MB/sec. Pretty sure it's not the fault of the software, but rather of other factors (drives are in external dock connected via esata, other programs running, etc.)

So I am definitely looking for a program that would verify very large files FAST. I wonder if there is a file copy program that can generate hashes for source and destination files during the file copy? Or could that be trusted?

Anyway thanks for the links. Will definitely try them out.

Teracopy has a verify option which generates hashes during the copy/move process.