When a cloudHQ sync runs into a file that exists in both the target and source cloud services, but this file was never synced through cloudHQ or file was changed on both location simultaneously, cloudHQ will do the following:

• cloudHQ will first compare files:
  • If source and target storage systems support the same hash/CRC algorithm, cloudHQ will use it for comparison.
  • If source and target systems don’t support the hash/CRC algorithm, cloudHQ will download files from both the source and target cloud services and compare them.
• If the files are the same, cloudHQ will catalog them. The catalog means that cloudHQ will register them in the database and leave the files unchanged.
• In the files different the following will happen:
  • In case of two-way sync, cloudHQ won’t try to merge the files. Instead, cloudHQ will save two versions of the file and label the older one as a “conflicted copy.” This way, all changes will be preserved. The filename of the second version (“conflicted copy”) will be the same as the first but appended with “conflicted copy,” the name of the service responsible for the conflict, and the date that the conflict occurred.
  • For one-way sync, the algorithm works like this:
    • If the source is newer than the target, then the source will replace the target.
    • If the target is newer than the source, we’ll make a “conflicted copy”.