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You Can Copy Files 'Once Only' (from Source to Target)

Consider the following scenario:

Files are present in a folder (the source) and they need to be copied to a target folder. Once the files are in the target folder they can be moved away by some further processing. However, even if the files in target folder are removed, the same file must not be copied again from source to target by ViceVersa.

Only if it changes in source, the same file must be copied again after the initial copy: we need to copy the files from source to target "once only".


This requirement can be satisfied by using ViceVersa in two different ways:


A)
By using the ‘no rescan’ target option in ViceVersa. With this option ViceVersa does not rescan the target after the initial scan, so it does not know that the file was removed, hence it will not copy the same file again from source unless it changes after the initial copy.
This setup works fine, but it requires ViceVersa to use a tracking database, and if the tracking database is damaged or lost (unlikely), the files will all be copied again.


B) A second approach is available since ViceVersa version 3 build 3005. Making use of the Windows Archive Bit. The new option is called “Copy source files once only, using the archive bit”.

When this new option is enabled:

- ViceVersa will only copy files that have the Windows archive bit set, and exclude the rest.

- Then, once the files are successfully copied, ViceVersa will clear the archive bit so the files will not be copied again next time unless they change, even if the corresponding target file is removed from the target.

Since the archive bit is only set by Windows when a file changes or on a new file, and it’s reset by ViceVersa after copying the file when the option “Copy source files once only, using the archive bit” is enabled, this will result in a file being copied only once from source to target, unless its contents change, even if the corresponding file in target is removed.


This new option is available in profile settings -> advanced settings -> more settings and requires ViceVersa version 3 build 3005 or newer.

User Comments
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infodan36 -  11-Jun-21
Hello,

I use your 3005 version under Linux via Wine, so I don't know if all the functionnalities work the same manner as in windows.
I tried your new "copy source files only, using archive bit" feature.
I put 2 folders as a test with 5 text documents named A/B/C/D/E, I checked that new field in the options, when deleting C file from the target, now indicating "removed" then I synched it with the source, and the C file was removed from source as well...
Same with box unchecked this time, I saw no difference in the process, C was removed from source. I don't really comprehend what this feature brings to me or I did something wrong ???
thanks for your help
TGRMN Software -  11-Jun-21
Hi, usually the new option "Copy source files once only, using the archive bit" is used with one of the replication methods to copy files from source to target "once only".

This option will exclude files that have been copied once "by ViceVersa" (ver 3 build 3005 or newer) by excluding files that have the archive bit cleared and indeed the archive bit is cleared by ViceVersa upon copying the files successfully. That will result in a copy once-only operation, regardless of the corresponding target file being removed or not.
infodan36 -  14-Jun-21
Thank you for the reply

However I would advise you to make a short video (like the demo video) that you could upload to your site showing the potentiel user/buyer the benefits from all your improvments or features for a new version, that would be more telling...

As to me, if I switch from the version 3003 to 3005 whithout checking this option, will I be safe ? (I would not like to make fatal errors) I use it the simpliest way mainly to back up mirroring source to target with no archives

By the way, any chance Sha256 could replace CRC any time soon ? or a trying Linux version ?

my 2 cents
thanks
infodan36 -  14-Jun-21
Hi

I have noticed something not really easy-going with your software about CRC option

Let's suppose I copy 99 files from Folder A to Folder B checking CRC option. All goes fine.
Ok, well if I add a new file to Folder A, and I would like to mirror it to Folder B, I cannot CRC check it alone, I have to chose to recheck again the whole 100 files. Could it be possible to kind of snapshot the 99 files and just CRC check the 1 new added ?

thanks again
TGRMN Software -  14-Jun-21
Hi,

The new option "Copy source files once only, using the archive bit" is completely optional, it is not required at all, it is only needed in a specific scenario to copy the source files once only in case the target files are removed by some further processing and you do not want to re-copy the source files to the target again.

Thank you for the feedback re videos, we will look into creating more videos for ViceVersa.

Re SHA: There is an option called "Use also SHA-256 hash for comparison". This will use both CRC and SHA-256.

If you only wish to compare CRC for newly copied files, and not for already copied files, leave the comparison method set to "Size and Timestamp" and enable the option "Verify copy operation by checking CRC".
infodan -  17-Jun-21
Thanks for the reply, but I meant SHA256 does not stand as comparison method contrary to "size and timestamps" and "CRC". The output number of SHA256 does not even show it the dashboard contrary to CRC which does show. Moreover you cannot extract the snapshot of all "SHA256ced" files and store them into a csv file for archiving purpose, standing as a rock solid list of each file. I mean I would like to get sure that my files are backed up, listed and Sha256ced (checksummed and snapshot) in a directory or a database that would be used for checksumming purpose in case a file gets further silently corrupted. I would further increment that list with new files. (I was thinking of a relevant list like the software KAREN DIRECTORY does) thanks a lot.
TGRMN Software -  20-Jun-21
When the SHA256 option is enabled the SHA256 algorithm is always used together with the CRC values. However, the CRC itself is safe enough for file verification and a very fast checksum: collisions for two different files are very rare and it is a good balance between speed, storage memory required, and efficiency.
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Author: TGRMN Software

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