i want to sync files from left pane to right pane for at 100 % backup. Left pane is a NAS server and right pane is an external USB Hard drive.
Whats the best way of comparing files for backup ?
I synced via Opus but after the synd i selected properties in both panes and can see that the file numbers are different. I chose "Comparison date (different).
I also tried "Comparison Byte Comparison" and in this case Opus kept finding files to sync eventhough i via that method synced from left to right, hence it should not be possible that Opus found any differences, right ?
I dont feel confident that the backup is 100 % safe because of these discrepancies
Sync panel setting was the culprit here i think, there was a filter which disabled sync of db files, i coud not see that because the filter had no name just said ".
But that still does not explain why setting "byte comparison" keeps telling me that there are files to sync although a sync has just been done.
Why is that any idea ?
Further, whats the best way of comparing files for backup regarding comparison mode?
sync panel setting herem also shows things to sync:
We need examples, else we're left guessing. The byte comparison option isn't selected in your screenshot, so that can't be the config that was used. We also can't see any examples of files that are identical but that it still wants to sync.
Have you checked that the files really are identical? E.g. Using Edit > Calculate MD5 Checksums. Sometimes there's something on the system monitoring e.g. new media files below a directory and making edits to their metadata automatically, for example.
Are the two files in the same path on both sides? That has confused people before, where it's really talking about copying a different file (with the same name but in another subdirectory).
no as i said i used differetnt settings one was byte comparison, which as i said caused endless detection of changed files and then the one on the screenshot.
Ill test reg byte compariosn again for test samples.
any advice in generel on whats the best way of comparing files for backup regarding comparison mode?
PS i use Opus 13 pro, dont know why system says ver 11, how to change that ?
The best way of comparing files for backup depends on your specific use case and how long you want the operation to last. Generally, the faster, the better.
You could have to use different modes on different locations on your computer.
The most precise will be byte comparison, but it can also be the slowest, especially if you're backuping large folders with large files where only a few can be different from one backup to another.
For every unchanged file, it will require reading every file to the last byte, both in source and destination to conclude it's the same file
If you're dealing with lots of text files (logs) that only tend to grow, byte comparison will be long too, with no advantage over date comparison
If the source or (more likely) the destination is on a remote device (NAS, another computer accessed by network share), you'll add network bandwidth limit (and usage) in the mix !
You then have mainly 2 criteria to use : dates & size with combinations of those 2 and their options (only smaller, only larger, more recent, just different date).
Those will be faster and can be enough in many situations (something like "difference in date or size" may suit many needs).
So, in the end, the best comparison mode ... is the one that suits your context.
Sorry if that answer disappoints you, but I'm afraid there is no better answer.
I'll let someone from GP Software answer as I can't remember how I did it.
Only one remark, there's no such thing as Pro or Light in Opus 13, it's just "Opus 13"
