Drobo, NTFS, GPT, MFT, and “The file or directory is corrupted or unreadable” (or “How I had file corruption and think i’ve fixed it”)
In the house I have a Drobo (box that takes hard drives), connected to a DroboShare (gives the drobo a USB to network connection), hooked up to the router. This keeps around 3Tb of movies and tv that we play through the AppleTv (running CrystalBuntu).
Anyway, recently I had a particular folder (Kids Films > W) that Windows Explorer (or Command Line) just wouldn’t see. Strangely, if you forced the address into explorers address bar the folder would open. Then a few other folders wouldn’t open and couldn’t be deleted.
The droboshare isn’t great at accessing the filesystem (for debug and diagnostic) so I hooked it straight up to the macbook (over USB). The same folders caused the same problems. Running ChkDsk would reach a specific point on stage two then hang consistently.
At this point I would have been happy to delete the affected folders just to clean them up, but no joy. Also I now found myself unable to get into the Kids Films folder at all. Two fantastic tools came to the rescue.
TestDisk (http://www.cgsecurity.org/wiki/TestDisk) was able to read the GPT partition, gain access to the Kids Films folder, and copy the contents over to another drive. All this whilst windows couldn’t get near the folder.
DMDE (http://softdm.com/) was able to see the Kids Films folder, but found it to be empty, however, within the Tools folder there is an option to repair the NTFS Index. DMDE is able to do this by bypassing windows NTFS driver in place of its own and locking the drive to allow it to write. It was able to recover each of the inner folders and files.
It took several hours of digging around the web to find the right tools and several false starts, but in the end TestDisk and DMDE were the saving grace (and helped keep a five year old happy !)