Conflicted copy of files on DropBox

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SUMMARY

  • Backup often!!! e.g. with Shift+F12 (see: Backup)
  • Never use the same collection on two computers at the same time! You can use two PCs only if you make a full copy of a collection, or the collection is fully synchronized, and you make sure you work only with one copy at a time.
  • Never synchronize or backup files while learning!
  • Be careful with DropBox! You can easily generate conflict files!!!
  • Be careful with Google Drive. See: Problems with DropBox and Google Drive

important

YOU CANNOT TRUST YOUR VITAL DATA TO ANY MEDIA!!! YOU NEED MULTIPLE BACKUPS OR YOU ALWAYS RISK LOSING PRECIOUS FILES!!!!

problem

anonymous wrote:

I had a crash. SuperMemo showed a fatal error and asked me to repair the collection. I did the repair and, to my horror, I saw many errors displayed by the program. After the repair, the collection seems to be ok but I see two problems:

  • all my repetitions being in April 2015!!! they should come today!
  • my forgetting curves have been reset (as if I never worked with the program)

If I repeat Repair collection, it says "no errors". I checked your FAQs and you suggest that I should restore my most recent backup. Unfortunately, I do not have a backup.

suggestions

  • please submit your collection urgently via mail for inspection
  • it is clear that the crash must have deleted or reset the mail collection file collection.kno
  • without a backup of that file, the data is most likely lost! however, your collection should be recoverable with some help
  • you will need to start building your forgetting curves from scratch, however, default curves will work well to (it is as if you moved back to an older version of SuperMemo)
  • repetitions moved to Apr 2015 mean that SuperMemo discovered your "first day of learning" set to zero and set it to the current date instead. There is no option to set that date manually. You will need help with that.

collection

Thank you for your collection. You may need to review your strategy for working with SuperMemo as the collection is jam-packed with "conflicted copy" files from DropBox. Some of conflicts are very serious. For example, you have conflicting text.rtx files that range from 300 to 760 kB. There are significant differences and this probably means that you have lost lots of work by working on different copies of the collection on different computers with DropBox interfering with that work all the time.

conflicted copy

Definition of conflicted copy from DropBox: "If two people change the same file at the same time, Dropbox won't try to merge the changes. Instead, it will save the original file as well as a second version which has the same name but is appended with "conflicted copy," the name of the person or computer responsible, and the date the conflict occurred. By creating a conflicted file, Dropbox ensures that all changes are preserved and nobody will overwrite another person's hard work".

Naturally, if you got dozen of conflicted files, it is not humanely possible to reconcile them all into a working collection without loss of data or integrity.

KNO file reset

Your files *.KNO and OptRec.dat have been filled with zeros. This might be a result of file lock conflict with DropBox. This also means that you will almost certainly lose some data. For example, your forgetting curves will be reset to default. In other words, SuperMemo will need to learn about your memory from scratch. This will not result in a significant slowdown to learning though.

ANSWER

You will receive your fixed collection via FTP download.

Please remember:

  • Backup often!!!
  • Never use the same collection on two computers at the same time!
  • Be careful with DropBox (preferably use it only to transfer files between computers, e.g. with File : Copy collection)

technical

Due to a conflict with DropBox synchronization, your KNO and OptRec files have been reset to all zeros. Upon starting SuperMemo, it should have warned you of fatal errors in data. That would be the moment to return to your recent backup. As Memorized=0, SuperMemo set the first day of the learning to today (Oct 20, 2013 in your case). As you actual start up date was Apr 29, 2012, all your learning process was set in a shifted timeframe (all dates in SuperMemo are relative to the first day of learning). SuperMemo cannot automatically resolve the conflict between KNO first date and the timeline record as these may differ for many reasons. This is why you needed a manual intervention with your collection. Once the first date was set as per the timeline record, you collection was easy to fix with File : Repair collection.

The good news that the size disparity between text.rtx conflicting copies was a result of compression made by Repair collection. After doing repair on both version, the size was the same! This means that you were lucky not to lose any texts/items.

Followup

OK, downloaded, did a review session just now, and yay! It works perfectly!

See also