In the actual case I had a directory containing about 13 files that were created under Linux. They were a few levels down from the root of the NTFS drive in a directory that unfortunately had a name ending with a ?

The copying was done not on the Linux machine but on a Mac as I needed to free up some space on the NTFS drive and I had plenty of space on a APFS drive. So I dragged and dropped the top level directory from the MacOS finder from the NTFS drive to the APFS drive. Some time later the copy was complete and I moved the NTFS  drive back to Linux and removed the files I thought I'd copied.


I don't have APFS drivers for Linux so I can't look at that drive other than on a Mac.


Sometime later I wanted one of those 13 files, went to the APFS drive and couldn't find them. They were not on the NTFS drive either because I had erased them assuming the copy had worked.


My expectation is that when an OS claims support for a disk format it should actually work. Being able to create files under Linux but not access some under MacOS is a problem.


I now have Paragon NTFS on the Mac which gives read/write NTFS access. This makes the problem worse because I can copy/move folders on the NTFS drive and loose problem file/directories again without warning. I contacted Paragon and they software is only used when writing to NTFS. They rely on the native MacOS functionality to read the drive.


When raising problems with companies I find it useful to give a simple set of steps to reproduce an issue so they can quickly test and evaluate what may be going on.


Apple unfortunately do not seem to have a mechanism to just report an issue hence my post here. Hopefully at least others will now be aware that there is an issue an take steps to ensure they don't suffer any data loss as a result.


The following full example is using an NTFS formatted USB pendrive.

on Linux:


/media/james/NTFS XFER$ mkdir -p test/directory_1

/media/james/NTFS XFER$ cd test

/media/james/NTFS XFER/test$ mkdir directory?

/media/james/NTFS XFER/test$ echo "Hello World" > directory_1/file1.txt

/media/james/NTFS XFER/test$ echo "Hello World again" > directory?/file2.txt

/media/james/NTFS XFER/test$ ls -al *

'directory?':

total 1

drwxrwxrwx 1 james james 152 Jun  4 20:03 .

drwxrwxrwx 1 james james 256 Jun  4 20:02 ..

-rwxrwxrwx 1 james james  18 Jun  4 20:03 file2.txt


directory_1:

total 1

drwxrwxrwx 1 james james 152 Jun  4 20:03 .

drwxrwxrwx 1 james james 256 Jun  4 20:02 ..

-rwxrwxrwx 1 james james  12 Jun  4 20:03 file1.txt

 

The drive is ejected an connected to the mac:

natsuki:test james$ cd /Volumes/NTFS\ XFER/test/

natsuki:test james$ ls -al *

ls: directory?: No such file or directory

directory_1:

total 1

drwxr-xr-x  0 james  staff   0  4 Jun 20:03 .

drwxr-xr-x  0 james  staff   0  4 Jun 20:02 ..

-rwxr-xr-x  1 james  staff  12  4 Jun 20:03 file1.txt

natsuki:test james$ ls -al

total 16

drwxr-xr-x  0 james  staff     0  4 Jun 20:02 .

drwxr-xr-x  0 james  staff  8192  4 Jun 20:02 ..

drwxr-xr-x  0 james  staff     0  4 Jun 20:03 directory_1


the line "directory?: No such file or directory" is a hint that at some level MacOS may know about that directory


Using finder the test directory is copy+paste - i.e. a new "test copy" directory has been created (with no errors raised)


natsuki:test copy james$ ls -al *

total 128

drwxr-xr-x  0 james  staff   0  4 Jun 20:03 .

drwxr-xr-x  0 james  staff   0  4 Jun 20:02 ..

-rwxr-xr-x  1 james  staff  12  4 Jun 20:03 file1.txt

natsuki:test copy james$ ls -al

total 16

drwxr-xr-x  0 james  staff     0  4 Jun 20:02 .

drwxr-xr-x  0 james  staff  8192  4 Jun 20:08 ..

drwxr-xr-x  0 james  staff     0  4 Jun 20:03 directory_1


Notice this time there is no  "directory?: No such file or directory"

The drive is ejected and placed back under Linux

/media/james/NTFS XFER$ ls -al test

total 8

drwxrwxrwx 1 james james    0 Jun  4 20:02  .

drwxrwxrwx 1 james james 8192 Jun  4 20:11  ..

drwxrwxrwx 1 james james    0 Jun  4 20:03 'directory?'

drwxrwxrwx 1 james james    0 Jun  4 20:03  directory_1

james@misaka:/media/james/NTFS XFER$ ls -al test\ copy

total 8

drwxrwxrwx 1 james james    0 Jun  4 20:02 .

drwxrwxrwx 1 james james 8192 Jun  4 20:11 ..

drwxrwxrwx 1 james james    0 Jun  4 20:03 directory_1


So under Linux the original test directory contains two sub-directories however the "test copy" directory only has a single sub-directory.


Finally (on Linux) looking for the file in the sub-directory:

/media/james/NTFS XFER$ ls -al test/*

'test/directory?':

total 1

drwxrwxrwx 1 james james  0 Jun  4 20:03 .

drwxrwxrwx 1 james james  0 Jun  4 20:02 ..

-rwxrwxrwx 1 james james 18 Jun  4 20:03 file2.txt


test/directory_1:

total 1

drwxrwxrwx 1 james james  0 Jun  4 20:03 .

drwxrwxrwx 1 james james  0 Jun  4 20:02 ..

-rwxrwxrwx 1 james james 12 Jun  4 20:03 file1.txt

/media/james/NTFS XFER$ ls -al test\ copy/*

total 4

drwxrwxrwx 1 james james  0 Jun  4 20:03 .

drwxrwxrwx 1 james james  0 Jun  4 20:02 ..

-rwxrwxrwx 1 james james 12 Jun  4 20:03 file1.txt


We see that only file1.txt exists under "test copy", file2.txt is not.

In conclusion, when copying on the Mac neither directory? nor its contained file directory?/file2.txt were copied and no warning given.