Restore Permissions to external HDD To read/write NTFS (Windows-formatted) external HDDs on my Mac, I have installed FUSE for OS X (version 3.2.0) and NTFS-3G (version 2015.3.14, installed with homebrew and the instructions from NTFS-3G). I have selected the 'MacFUSE compatibility layer' because it is required by veraCrypt (from https://veracrypt.codeplex.com/). 

Copying to/from the Mac to the NTFS HDDs works as expected. However, I can no longer use the Disk Utility's "First Aid" utilities (to correct permissions, to correct errors when the HDDs get incorrectly dismounted). The disk utility options are now 'greyed out' for my HDDs. These options are still available for my internal SSD and for my SD card, so the disk utility is not 'broken'. The HDDs are also fine: they work correctly and I can still fix them on Windows. The problem (the only one I can see so far) is that I can no longer fix my external HDDs with the Mac's disk utility.

I'm currently on OSX Yosemite. Here is the diagnosis from the Disk Utility:

    Name :  PatrickA
    Type :  Partition

    Disk Identifier :   disk2s1
    Mount Point :   /Volumes/PatrickA
    File System :   Windows NT File System (NTFS)
    Connection Bus :    USB
    Device Tree :   IODeviceTree:/PCI0@0/XHC1@14
    Writable :  Yes
    Universal Unique Identifier :   54D2798C-E724-4810-B621-F1358C19DC48
    Capacity :  1 TB (1,000,169,537,536 Bytes)
    Free Space :    245.04 GB (245,044,764,672 Bytes)
    Used :  755.12 GB (755,124,768,768 Bytes)
    Number of Files :   130,742
    Number of Folders :     0
    Owners Enabled :    Yes
    Can Turn Owners Off :   No
    Can Repair Permissions :    No
    Can Be Verified :   No
    Can Be Repaired :   No
    Can Be Formatted :  No
    Bootable :  No
    Supports Journaling :   No
    Journaled :     No
    Disk Number :   2
    Partition Number :  1


As you can see above, my HDDs (all of them) can no longer be verified or repaired. I was always able to do that before reinstalling FUSE and NTFS-3G. The above diagnosis is identical for all 12 of my HDDs. 

I tried to reset permissions, but was denied:

vsdbutil -a /Volumes/PatrickA
vsdbutil: no valid volume UUID found on '/Volumes/PatrickA': permissions are disabled.


I read somewhere that hfs.util can regenerate a UUID, but that didn't work.

diskutil info /Volumes/PatrickA | grep "Device Identifier"
Device Identifier:        disk3s1
/System/Library/Filesystems/hfs.fs/hfs.util -s disk3s1


Any suggestions? Thanks!

UPDATE I came across suggestions on how to use the diskutil from the command line. Here is the error message I get:

diskutil verifyvolume /Volumes/PatrickA/
Error starting file system verification for disk2s1 PatrickA: Invalid request (-69886)


I have also not been able to get smartctl to do anything useful with the volume:

smartctl -c /Volumes/PatrickA
smartctl 6.4 2015-06-04 r4109 [x86_64-apple-darwin14.3.0] (local build)
Copyright (C) 2002-15, Bruce Allen, Christian Franke, www.smartmontools.org
Smartctl open device: /Volumes/PatrickA failed:


I came across a suggestion that a third party driver is needed to diagnose external drives on a Mac OS X (I do not know if this is generally true). The SAT SMART driver (available at https://github.com/kasbert/OS-X-SAT-SMART-Driver) extends the standard driver behaviour by providing access to drive SMART data. I was successful in changing the SMART status of my HDD to "Verified." But this does not appear to have helped much as the errors reported above still appear.
The community NTFS-3G driver in conjunction with Disk Utility doesn't allow you to repair the file system of an NTFS-formatted volume nor its permissions. 

The file system repair feature is only available in the commercial Tuxera NTFS for Mac edition (based on the NTFS-3G driver) - either by using Disk Utility or Tuxera Disk Manager.

In the default configuration the files and folders of the mounted NTFS volume are owned by the effective user and group of the mounting process - the common settings are 777. This means all OS X users have full access to the volume or: Permissions are ignored!

At least in Linux using the community driver this can be overridden by modifying the mount options and user mappings (also: Advanced ownership and permissions). I don't know if this also works in OS X. The commercial Tuxera NTFS for Mac doesn't mention anything like this in its manual.