CRC Problem?

[malega]

I am evaluating VV 2.0.

I am now doing a CRC check. My hard drive has about 63,000 files.

However, the CRC check is going on now and claims there are more than 300,000 files in my target drive (a brand new external drive where I mirrored by hard drive using VV2.0.

right now the VV message says "checking tracking database" and it is comparing CRC values (the CRC value is up to about 82 billion).

I have about 60 gigs of info on my hard drive.

Why does VV list more than 300,000 files when there should only be 63,000?

The target drive contains the right amount of info (about 60 gigs), so it seems like the copy is accurate (and I didn't have any errors with the timestamp check).

Thanks.

[TGRMN Software]

Hi

CRC and Timestamp comparison list the same amount of files. Are you sure you are comparing the correct source and target?

thanks
_________________
--
TGRMN Software Support
http://www.tgrmn.com
http://www.compareandmerge.com

[malega]

I thought that the files compared were the same as I did it right after I made the original backup.

However, I am new to the program, and I am making a new backup and am currently running a CRC check. I'll let you know if there are problems.

Second related question: how reliable an indicator is CRC as compared to the timestamp.

In other words, if I have 65,000 files, what are the chances one or more of those files are corrupted on the copy, but this corruption will not be detected using timestamp, versus the chances running CRC?

Assuming for example that the backup media has no defects (I usually use an external hard drive), should I have 100% confidence that every single file on my backup media is readable and an exact duplicate of the original file? And if so, how much does that confidence decrease if you only use the timestamp method of comparison?


I have done a quick check on the Internet and I have not found a direct answer. It also appears that there are different kinds of CRC checks. Which version does VV use?

I have used Backup Mypc for number of years, and I have had occasion to restore my hard drive several times, and have not had any problems. So far, I like your program and right now ongoing reliability is my primary concern.

It seems like having the ability to do a crc comparison increases the reliability, but it is not clear by how much.

Thank you

[TGRMN Software]

CRC checks are useful for possibly unreliable media, such as Internet, DVD, CD. HD are very reliable. I would not use CRC comparison in your situation but just timestamps, becuuse CRC takes too long. Occasionally, you could check file CRC for data verification. For instance when we backup the ViceVersa source code to external drive we use timestamps and occasionally we verify the backup with CRC. ViceVersa uses CRC32.
_________________
--
TGRMN Software Support
http://www.tgrmn.com
http://www.compareandmerge.com