- Aug 20, 2004
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Originally posted by: NightCrawler
Acronis True Image 8.0 is tha bomb.
Originally posted by: NightCrawler
Acronis True Image 8.0 is tha bomb.
Originally posted by: Elixer
Hold on, last I checked, True Image doesn't do true image verifications. Ghost does.
What I mean by true image verifications, I mean it compares what is written on the device against the original.
True Image verifies that the file is correct, but does NOT compare against the original source. It does some kind of CRC check, nothing more. At least this was the case when I used it, maybe they fixed this.
I lost data do to that fact. It was lucky I did 2 backups(one with TI, one with ghost), or I would have been pretty mad.
Oh, Is this new ghost really ghost, or is it really Drive Image, since they bought them out.
Interesting to know, thanks. That was one reason that I stopped using Retrospect Express Backup, because it lacked user-initiated binary-compare features, it too only did the "backup media CRC-check" thing. How useless!Originally posted by: Elixer
Hold on, last I checked, True Image doesn't do true image verifications. Ghost does.
What I mean by true image verifications, I mean it compares what is written on the device against the original. True Image verifies that the file is correct, but does NOT compare against the original source. It does some kind of CRC check, nothing more. At least this was the case when I used it, maybe they fixed this. I lost data do to that fact. It was lucky I did 2 backups(one with TI, one with ghost), or I would have been pretty mad. Oh, Is this new ghost really ghost, or is it really Drive Image, since they bought them out.
For two cases in which a true binary-compare facility is both useful and necessary - consider the case of an overclocked or not fully stable system. If you read the data from the source drive, and then during the process of calculating the CRC and writing it to the backup medium, something gets corrupted, then you will never know - because the CRC is being computed over the incorrect, already-corrupted data.Originally posted by: NightCrawler
Not sure what you mean by true verification but a checksum is either correct or it's not. Can't be a little pregnant.
Originally posted by: kamranziadar
Amazon has Norton Ghost 9 Disk Imaging software for $4.99 after rebate for upgraders/crossgraders, free shipping.
$60 rebate Exp 12/25/04
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Originally posted by: VirtualLarry
For two cases in which a true binary-compare facility is both useful and necessary - consider the case of an overclocked or not fully stable system. If you read the data from the source drive, and then during the process of calculating the CRC and writing it to the backup medium, something gets corrupted, then you will never know - because the CRC is being computed over the incorrect, already-corrupted data.Originally posted by: NightCrawler
Not sure what you mean by true verification but a checksum is either correct or it's not. Can't be a little pregnant.
Another, and perhaps more-useful application, is taking an older backup, and then running a binary-compare against the current copies of files stored on the HD. This is a great way to detect bit-rot, or possibly even a malware infection. I've found some instances of data-corruption this way, and replaced the hardware. It can be quite a lifesaver. Any program that cannot do that, is crippled and broken and should never be used for any sort of critical backup purposes whatsoever, IMO.
That is the way it should be. However, that is NOT the case for many backup programs. What they do is read the data, then dump the data. They do NOT compare the written data to the source data, it just makes sure that the datafile is OK, as in it just checks that the data file can be read back ok.Originally posted by: NightCrawler
Ok maybe I'm still not getting the idea here...
The order should be:
1. Caculate checksum of source material.
2. Backup source material.
3. Verify backed up data using the checksum.
4.{ optional } delete source material if need be knowing a good copy exist.
If the checksum doesn't match you know that the backed up data is corrupt and you can start over and make another copy.
Originally posted by: Elixer
That is the way it should be. However, that is NOT the case for many backup programs. What they do is read the data, then dump the data. They do NOT compare the written data to the source data, it just makes sure that the datafile is OK, as in it just checks that the data file can be read back ok.Originally posted by: NightCrawler
Ok maybe I'm still not getting the idea here...
The order should be:
1. Caculate checksum of source material.
2. Backup source material.
3. Verify backed up data using the checksum.
4.{ optional } delete source material if need be knowing a good copy exist.
If the checksum doesn't match you know that the backed up data is corrupt and you can start over and make another copy.
I guess a better way of putting it is, it checks the container to make sure it is ok, it *don't* check what is in the container to make sure that data is 100% the same.
If you ever used Nero backup (I sure hope you NEVER do), then what they do (as of v6) is read the data, write the data. verify the data. (so far so good), but on error of the verification, it tells you verification failed. Now it says insert another CD/DVD, and then it reads/writes/verifies again for however many CD/DVD it needs to dump all the data, then finally, at the very end when it is done, you find you still have the same amount of CD/DVDs it asked for. Even though 1 (or more) verification(s) failed. What does this mean? It means you just wasted XX # of CD/DVDs since it never re-wrote the CD/DVD when the verification failed!
I ended up with 8 DVDs that were useless. Thanks Nero!