Compare not working..on second use at least?

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Posts: 2
Joined: 21 Nov 2019

knowsey

I want to have 2 backups of my master music folder (400Gb) on 2 separate hard drives. I used free file sync for the first time just now and it worked immediately well on the first master copy to the backup – I was choosing compare (file and time) and the mirror options. Then I wanted to duplicate the same task for the second second backup drive. I clicked on compare again and for some reason it found every single file for back up this time when obviously 99% of them are the same. I'm not sure why it worked correctly the first time but not the second. Can anyone help ?
Posts: 2
Joined: 21 Nov 2019

knowsey

Also just tried to do it with my photos folder and same error - works fine for first back up but for the second it throws up every file in compare! Is this a limitation on the software use?
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Posts: 2248
Joined: 22 Aug 2012

Plerry

I suppose your "first backup" started with an essentially empty backup location and involved copying over the content of the source location to the backup location.
In which case things obviously would work fine.

You mention " it found every single file" and "it throws up every file in compare".
Obviously all files are Compared and (depending on the view) may show up in the Compare results.
What matters is the proposed action.
All files with compare result "right-side is equal to left-side" (the "="-icon) should have an action "do nothing" (the "-"-icon). If you do not want to see the "right-side is equal to left-side" Compare results, you can use the Select View feature (mid below the Compare results) to show or hide different compare result Categories.
When next executing the Sync, the actions proposed based on the Compare will be executed (unless manually modified). If everything was equal, your Sync will be over instantly, as no sync-actions needed to be taken.

If all files show up as being different (in time and/or size), and the proposed actions are to copy files over, then you may have another issue.
If your backup location is an (S)FTP location, it may be your (S)FTP server does not support retention of file dates. Any files copied over to the backup location will then have/get the timestamp of the moment of copying-over. And then obviously the left- and right-timestamp will differ in the next Compare. See here (item 2).
It may also be that you have different file-systems between your source and backup location. This may matter if there was a change in time (daylight saving time) in between syncs. See here.