Case-sensitive synchronization

[matteeffs]

I’m non-technical. I have 18 TB of data on an obsolete NAS; which I have to transfer to my new NAS.

My initial attempt to begin the process involved dragging and dropping a folder. Copying was interrupted eventually with the following dialogue box:
<<<You can’t copy because file has the same name as another item on the destination volume, and that volume does not distinguish between upper- and lowercase letters in file names.>>>

After researching the problem online, I learned the terminology is called “Case-sensitive synchronization”, and that an application like Free File Sync would solve the issue.

I donated, and installed Free File Sync, and I noticed after my first transfer that I had three error warnings about the same issue (worded differently though)

My question to the forum is whether the error warnings are generated; even though the case sensitive names are mirrored properly, or whether there is an adjustment I have to make to get the proper mirror? When I checked both files, they seemed identical, but the error message has confused me.

Thank you in advance for your help.

[xCSxXenon]

The issue you are facing is caused by using a file system that considers two similarly named items with different cases the same. This can't be fixed by FFS, or any other software. You need to format the destination to a format that supports case sensitivity or rename the files

[matteeffs]

Thank you very much xCSxXenon. Oh boy. This could be a very long transition of 18 TB to my new Synology NAS then. It only uses a file system called Btrfs. Again thanks. I'll find some way to manage this.