How to make macOS files survive an NTFS round trip?

[DominikHoffmann]

I am looking for advice on how to avoid issues. I would like to copy files from an HFS Plus (a.k.a. HFS Extended) volume to an NTFS volume. The criteria are:

1. Files that can be opened with Windows apps should be able to be opened.
2. Files that can’t be opened (iMovie projects come to mind), should maintain integrity, even if they are later copied back to a macOS volume, HFS Extended of APFS.

Is there anything I should keep in mind?

 

[Bigwaff]

I am looking for advice on how to avoid issues. I would like to copy files from an HFS Plus (a.k.a. HFS Extended) volume to an NTFS volume. The criteria are:

1. Files that can be opened with Windows apps should be able to be opened.
2. Files that can’t be opened (iMovie projects come to mind), should maintain integrity, even if they are later copied back to a macOS volume, HFS Extended of APFS.

Is there anything I should keep in mind?

First, macOS can't write to a NTFS formatted volume unless you have 3rd party drivers installed.

Second, I am assuming you wish to take the NTFS formatted volume (on an external drive) and attach to a Windows system? Whether files can be opened with Windows applications will be dependent upon the macOS software used to create/write the file and the Windows software used to create/write the file. No guarantees a "round trip" will work unless the software in particular supports a "universal" file format.

Third, by "should maintain integrity", I assume you mean macOS should be able to open iMovie projects stored on a NTFS volume that has been copied to an HFS+ formatted volume? I would assume so but iMovie projects are a package of files, not a single file on disk. The projects appear as a "file" in macOS but most likely will appear as a folder on NTFS file system.

You will have to experiment.. but, first, you need a macOS NTFS driver.

 

[DominikHoffmann]

You will have to experiment.. but, first, you need a macOS NTFS driver.

I will copy them from the Mac to the PC either via the network or a Windows VM through Parallels’s shared Mac folders.

I could preserve the Mac files doubly: just copy them over to the NTFS volume and then ZIP up the whole user folder on macOS. If anything later will have to be retrieved, the ZIPped folder can be unpacked on macOS, and everything (extended attributes, file packages, etc.) should come back. Am I thinking correctly? Other than the caveat of the additional required storage?

 

[Bigwaff]

ZIP up the whole user folder on macOS

Are you trying to archive or back up the macOS user account?

 

[DominikHoffmann]

Are you trying to archive or back up the macOS user account?

It’s an effort to archive a users’s 2013 hard drive contents. The user at some point between then and now switched to Windows. However, should he want to access very Mac-specific files by accessing them through a modern Mac, I’d want hime to be able to do that without having lost necessary metadata.

 

[chown33]

I recommend making the archived version of the data using:
1. a sparse-bundle disk-image.
2. the 'rsync' cmd to copy the data to the image.

The sparse-bundle's disk format should match the original. If original is HFS+, disk-image should be HFS+. Ditto for APFS.

The reason for using sparse-bundle is it lets you store the data on any medium, regardless of the underlying format. In other words, you can store an APFS original on a FAT32 disk, or on a NAS, or on a commercial storage service, and nothing will be lost.

When using 'rsync', make sure to use the -E option, and also run it using 'sudo', so absolutely everything is copied to the disk-image. Without 'sudo', original ownership might not be kept.

I also suggest running trials first, using a sparse-image with proper format, but only copying a small number of files, but ones that have extended attributes or ACLs that might be lost if ZIP or Finder-copy were used. This will let you work out exactly what 'rsync' options to use, and confirm that the replica is exact. You can also check exactly what a ZIP or Finder-copy loses.

Here's an example of a folder on my disk with an ACL:

drwx------+  4 plover  staff  -  136 Jul 15 18:32 .
 0: group:everyone deny delete
drwxr-xr-x@ 39 plover  staff  - 1326 Jul 15 18:13 ..
 0: group:everyone deny delete
-rw-r--r--   1 plover  staff  -    0 Nov 23  2012 .localized
-rw-r--r--@  1 plover  staff  - 9686 Jul 15 18:13 Pi-log.txt
    com.apple.TextEncoding      15 
    com.apple.metadata:kMDLabel_3fvqtyttvmel7wfftcnejrwozm     313

The replica on the disk-image should have all the same xattrs, modes, ownership, and ACLs.

Typical examples of folders with ACLs are Documents, Desktop, Library, etc. in a typical home folder.

The cmd that shows all the infor is ls -leaO@


If saving space is important, then make a disk-image as noted above, then convert it to a compressed read-only disk-image. This will be a single file, unlike sparse-bundle, which is a directory with "band files" of 8MB in it.