What happens when both left and right files have changed? RRS feed

  • Question

  • I have been using SyncToy successfully every day for years and, by and large, find it very good (currently using v2.1).
    However, last week, a very strange thing happened. Without going in to a long story, by accident both the left and right versions of a particular file had been amended (at different times and in different ways) since the previous synchronisation. I did not realise this when I came to synchronise the two folders but this happened without incident and the older of the two versions of the file was replaced by the more recent version.
    Surely when both versions of a file have changed, the software should spot this and flag up an error message? Is this what SyncToy should do in this situation or not?
    Wednesday, January 26, 2011 5:04 PM

All replies

  • In the case you modified a file both in the left and right and are using the Synchronize action, SyncToy will detect a conflict between the two files, and pick the file that was last modified as the conflict winner. This version will be the one that will persist in both left and right locations.  The other version of the file will be moved to the recycled bin.

    For example you have file A_left and A_right, and modified first A_right, then A_left, and then synchronized.  After synchronization, A_right will be in your Recycle Bin, and A_left, will be both in left and right endpoints.


    Maria del Mar Alvarez Rohena Microsoft Sync Framework
    Wednesday, February 2, 2011 7:37 PM
  • Maria - I can understand the logic behind this decision but I do not agree that the logic is sound. There is no way for Sync Toy to know which version of the file is correct. IMHO it should just flag the condition in a very obvious fashion and then let the human make the decision. It is highly possible that the changes made in both files need to be preserved and only the human can make this decision. Just to assume that the file with the latest time stamp is the most correct version is false.
    • Proposed as answer by ItsLex Saturday, March 19, 2011 6:26 PM
    Thursday, February 3, 2011 5:21 AM
  • Yes, I agree with jgt. This behaviour is not apparent enough to the user in either the webpage or help files! This needs to be fixed. Also, behaviour that notifies the user of a change in both since the last synch with options for action. One synchronize behaviour could be a default in which a new file is created at both locations with filename "oldfilename_mod1" and "oldfilename_mod2". This would allow for resolution of the issue.

    Can this be added soon?

    Saturday, March 19, 2011 3:51 PM
  • Agreed here too. Any chance of a response from Maria or someone else from Microsoft? This really does need fixing asap.
    Monday, March 21, 2011 6:33 PM
  • I would like to see this changed as well.  I am currently setting up weekly backups to an external hard-drive just in case SyncToys updates something I was not expecting.  Other than this issue, I am very grateful for the program.
    Tuesday, March 22, 2011 7:36 PM
  • There is really a need for a Version Nr. 3. So much potential.
    Thursday, March 24, 2011 1:11 PM
  • After nearly 3 months, is there no chance that someone from Microsoft could respond to, or comment, on the above. It would be really helpful to know if an update which fixes this issue will soon be available.
    Friday, June 10, 2011 12:41 PM
  • I agree with all of the above.  I just recently dowloaded it and still no fix.  I guess Microsoft has had their heads up in the clouds!
    Thursday, October 27, 2011 4:29 PM
  • After another 5 months, is there still no chance that someone from Microsoft could respond to, or comment, on the above. It would be so helpful to know if an update which fixes this issue will soon be available, or if v2.1 is the last we shall ever see of SyncToy.
    Monday, November 21, 2011 6:08 PM
  • I agree with the above. We use SyncToy as a company. Its an essential part of working out of the office. We would buy a product with more functionality.

    The functionality of asking what to do when a file is updated in both the left and right folders has been present in windows offline files for a long time. At the moment it too easy to delete someone elses modifications.


    Does no-one at Microsoft need access to a whole project directory while out of the office?

    Saturday, November 26, 2011 5:59 PM
  • I was so frustrated with the lack of response on this issue that I recently emailed the Head of Microsoft in the UK about it. Although he passed it on to a minion, she quickly manged to get a response from 'one of Microsoft's SyncToy specialists' as follows:
    "SyncToy is no more under active development and in the foreseeable future it may not be either.
    The problem this customer and others on the SyncToy forum thread have run into is by design – when there is a conflict between two updated files, SyncToy will pick the last-written one as the winner (even if users checks the option to compare file contents – default is timestamp comparison). Users can check the option on SyncToy where by all files being overwritten or deleted are sent to the recycle bin on the volume. Unfortunately, SyncToy as is not designed to leave conflicted files unsynced and alert the user about them.
    There is a rather hard work around but that involves user writing their own tool.
    SyncToy is based on Microsoft Sync Framework’s FileSyncProvider component. Users can write a simple application that uses FileSyncProvider along with SyncOrchetstrator to specify their own conflict resolution policy to resolve or leave conflicts.
    Here are some useful links for someone who would like to develop their own solution:
    This may not be the answer I was hoping for but at least we know where we now stand regarding SyncToy's future development (or lack of it)!
    I'm afraid I'm not technically up to writing a tool to overcome the problem. However, if anyone else who reads this wants to have a go and has any success, perhaps they'd let us all know.

    • Edited by Victor Delta Saturday, December 3, 2011 12:06 AM
    Saturday, December 3, 2011 12:05 AM
  • Well, this thread definitely answers the question I was about to ask about conflicts.  I had assumed that SyncToy might be a well supported app within Microsoft, but obviously that's not the case.  I have used MS's Briefcase function for a long time, and at least it detects conflicts, but there are other problems with it that make it a little user-unfriendly. 

    Does anyone have any other suggestions on good sync'ing apps?  My needs are pretty simple; just want to have access to varoius files on my desktop while I'm traveling, and I just sync them on my laptop before and after each trip.  Any suggestions would be appreciated. 

    Wednesday, April 25, 2012 12:32 PM
  • Hi Todd

    You might find this article helpful on the subject http://www.techsupportalert.com/best-free-folder-synchronization-utility.htm

    I've tried these and several other syncing utilities but, in the end, stuck with SyncToy - despite it's imperfections - as I haven't found anything better overall. However, as you say, I do find it odd that SyncToy doesn't flag file conflicts given that the earlier Windows Briefcase always did that. In the end, if you are disciplined about syncing immediately before and after travelling, you won't have a problem in practice (or, at least, that's how I manage to make it work ok!).


    Friday, May 11, 2012 11:17 PM
  • I have a folder-pair for testing SyncToy - folder A and folder B!

    I found out the following, I hope someone can confirm my comments:
    I created a txt-file named 1.txt in the folder A, after synchronization off course folder A and B included the file 1.txt.

    Then I renamed the file first in folder B to 11.txt and to 12.txt in folder A. So the last change was made in folder A.
    In my oppinion SyncToy should have taken the last known rename, but it didnt. In every case the folder B was the one with more weight!
    It didn't matter which folder I renamed first and last, in every case SyncToy decided to consider the rename of folder B.

    So my conclusion is that you should really avoid to rename the same file(s) in folder A and in folder B, SyncToy cannot examine this (although using Synchronization).

    Friday, May 18, 2012 1:32 AM
  • This Forum seems to be dead.
    Saturday, May 19, 2012 7:45 PM
  • I agree even though this is an old topic, however, the workaround is pretty clear.  Human intervention.

    Drag the one in the Recycle to a folder (Desktop?), rename it and place it where you want it.

    Not a solution but I am SURE you have done it.

    Wednesday, May 30, 2012 12:34 AM
  • FYI - SyncToy isn't as crude as this discussion implies. How SyncToy 2.1 deals with various conflicts is explained is explained in detail on the webpage linked below:


    Also, program offers more options than "Synchronize" -- "Contribute" for example will delete nothing at all. And although I've not thought this through in detail, it seems that one could use "contribute" in both directions -- in two jobs, reversing the left & right paths in each job -- to get the data synchronized without deletions.

    Another alternative might be the use of SyncToy v1.4, which included "Combine," a function which never deletes items -- just copies and, in the case of conflicts, renames. SyncToy 1.x had some bugs, however, so it would be wise to read the changelog for version 2.1 before deciding to rely on v1.4. Also v1.4 was made for XP & 32-bit systems, so on Win7 today, a successful install might require some experimentation with the "compatibility" tab options (accessible by right-clicking the setup or install exe file, and clicking "Properties" then the "Compatibility" tab).

    Personally, I find SyncToy 2.1 to be very useful as a backup program, using the "Echo" function. I just ran a backup of nearly all the folder pairs I have listed in SyncToy, and although the job took MANY hours (partly due to an old USB external drive enclosure & old EIDE hard drive), when it was done, it had copied close to one million files & folders, renamed nearly 2,000 of them, and put an additional 61+ GB of data on my external drive. And it needed no intervention. (Admittedly, I did periodically clean the system memory & file cache via my CleanMem program when the memory consumption entered the red zone, but that might've been due to other programs I was running, like my browser with numerous tabs and addons.)

    I do have criticisms, of course. I'd like to see the "Combine" function brought back. I'd like to see the program simply being maintained too, as I fear some undiscovered bugs might still exist, and I am relying on it as one of my backup programs. I'd also like to be able to edit all aspects of a job after it's been created. And I'd like to have the ability to combine jobs from the beginning -- so a single job would consist of multiple folder pairs.

    But I think I might as well be writing to Santa about this. Sigh.

    Wednesday, August 27, 2014 9:11 AM
  • Thanks for that JDPDX. After over 2 years of silence I thought this thread was well and truly dead!

    I don't think anyone thought that SyncToy was crude, indeed many folk - myself included - are still devoted users of it (despite it's lack of updates etc). However, the key point about how it deals with conflicts was that it doesn't notify the user when a conflict exists, let alone allow the user to choose which option should be taken. Even the old Briefcase programme did this (Windows 95?).

    Sadly I don't think it will ever be resolved - unless Santa can get the elves working on it...?

    Wednesday, August 27, 2014 8:05 PM