False detections when comparing

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Posts: 3
Joined: 14 Feb 2024

rds

Hi,

FreeFileSync is used to backup local files to an external hard disk and network drive.
The comparison of the data is based on file size and date, deviations are mirrored. Out of almost 5600 files, the same 32 files are regularly displayed as not yet synchronized.
The following has already been tried,
a) delete all data of the backup target and resynchronize. However, this does not change the fact that these 32 files are still displayed as not synchronized after (multiple) successful synchronization. The check has shown that the last modification date/time of these files actually differs from the original date/time in such a way that the modification time corresponds to the date/time of the last synchronization.
b) uninstalled and reinstalled FreeFileSync. Problem remains.

Any ideas?

Kind regards
Richard
Posts: 9
Joined: 7 Jul 2020

phhowe17

What (if any) errors are listed in the log after a sync?
What is the length of the full path & filename? Windows has issues with long paths?
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Posts: 3606
Joined: 11 Jun 2019

xCSxXenon

Also, you may be syncing to a location that breaks or discards the timestamps, thus subsequent syncs determine them as different over and over. Run a compare, and then look in the middle section, FFS will tell you why it considers the files different
Last edited by xCSxXenon on 18 Feb 2024, 15:35, edited 2 times in total.
Posts: 3
Joined: 14 Feb 2024

rds

@phhowe:
1) No erros at all
2) For example, C:\!lokal\Trend Micro\VA\Tools\SDelete.zip

@xCSxXenon
FFS considers the files to be different as the timestamp on the right side is newer. As described in initial post, for about 32 out of 5600 files synchronized on a daily basis the modification time of the synced file corresponds with the date/time of the last synchronization. The rest of the files synced do not have that issue.
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Posts: 2286
Joined: 22 Aug 2012

Plerry

This reads like some tool on the destination computer accesses and modifies (or at least changes the modified date of) said 32 files after they are written there.
E.g. some anti-virus software has the nasty habit of doing so.
As you write it is always the same 32 files, for a start you may look into identifying common characteristics of those 32 files, like file-type or specific location.
Posts: 943
Joined: 8 May 2006

therube

This reads like some tool on the destination computer accesses and modifies (or at least changes the modified date of) said 32 files after they are written there.
Agreed.

Sounds like, Recurring "Updates" That "Don't"
Posts: 3
Joined: 14 Feb 2024

rds

@Plerry, therube
I backup my data to an external HDD which is not monitored by any AV on a daily basis, and on a monthly basis to a network share which is monitored by an AV. For some time now, 32 files have been "out of sync" on the external hard disk, but only 24 files on the network share.
There is no common characteristic, it is manifold, e.g. exe, zip, pdf, txt, com, xlsx, png.
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Posts: 3606
Joined: 11 Jun 2019

xCSxXenon

Maybe those files in the source don't have valid timestamps, thus forcing the current date/time to be used.
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