Hi there,
I use FreeFileSync for several years now and all my backup are from my mac to external hard drives or a NAS using mirror synchronisation.
I recently set the same type of synchronisation (mirror) from my mac but to a pen drive. I realized that when I click on "Synchronise" all the folders and files are copied each time I do a back up and not only the new, deleted or modified files and folders. I don't understand why...
Thanks for your help!
Marcus
Mirror synchronisation to USB drive not working as others
- Posts: 3
- Joined: 14 Nov 2024
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- Posts: 2450
- Joined: 22 Aug 2012
If you run just a Compare in the FFS GUI, FFS will show the sync actions it intends to take and why.
Likely the timestamp of files written to the pen-drive differs from that on your mac,
and when running a Mirror sync that is ground for a renewed mac => pen-drive copy.
Likely the timestamp of files written to the pen-drive differs from that on your mac,
and when running a Mirror sync that is ground for a renewed mac => pen-drive copy.
- Posts: 3
- Joined: 14 Nov 2024
I thought about that... but how to fix this...?
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- Posts: 2450
- Joined: 22 Aug 2012
> how to fix this...?
That depends on your sync settings, and the reason the FFS Compare results give for wanting to recopy mac => pen-drive.
If you have the "Use database file to detect changes" checkmarked in your Synchronization Settings (F8), you may want to try removing that checkmark, and do without the database.
The database only works as intended if both the left and right side have stable file-IDs, which may not be the case for your pen-drive.
Probably the most sure way (in the sense of working correctly for your use-case) is likely to define a Custom sync variant in your Synchronization Settings (F8), without checkmarking "Use database file to detect changes".
• For the Difference category "Item exists left-side only" you select the Action "Copy new item to right" (the green arrow with +-sign)
• For the Difference category "Left side is newer" you select the Action "Update right item" (the green arrow without +-sign)
• For the Difference category "Right side is newer" you select the Action "Do nothing" (the gray minus-icon)
• For the Difference category "Item exists right-side only" you select the Action "Delete right item" (the green trash-can with minus-sign)
Not using the database prevents any problems with potentially unstable file-ID.
And using the Custom sync variant as described just above is (almost) identical to a Mirror sync, but the "Do nothing" of the 3rd bullet prevents any re-copying due to potentially more recent file-dates on your pen-drive than in your mac source.
That depends on your sync settings, and the reason the FFS Compare results give for wanting to recopy mac => pen-drive.
If you have the "Use database file to detect changes" checkmarked in your Synchronization Settings (F8), you may want to try removing that checkmark, and do without the database.
The database only works as intended if both the left and right side have stable file-IDs, which may not be the case for your pen-drive.
Probably the most sure way (in the sense of working correctly for your use-case) is likely to define a Custom sync variant in your Synchronization Settings (F8), without checkmarking "Use database file to detect changes".
• For the Difference category "Item exists left-side only" you select the Action "Copy new item to right" (the green arrow with +-sign)
• For the Difference category "Left side is newer" you select the Action "Update right item" (the green arrow without +-sign)
• For the Difference category "Right side is newer" you select the Action "Do nothing" (the gray minus-icon)
• For the Difference category "Item exists right-side only" you select the Action "Delete right item" (the green trash-can with minus-sign)
Not using the database prevents any problems with potentially unstable file-ID.
And using the Custom sync variant as described just above is (almost) identical to a Mirror sync, but the "Do nothing" of the 3rd bullet prevents any re-copying due to potentially more recent file-dates on your pen-drive than in your mac source.
- Posts: 3
- Joined: 14 Nov 2024
Thank you for taking the time to give me so much details. It's all clear for me and on top of it I learnt! No regret I made a donation few days ago and will probably again in the future.
Best regards,
Marcus
Best regards,
Marcus
