I put this question:

recover files from HSF+ USB External HD, test on CentOS 7 to diagnostic

And this


I'm trying to recover my data files from a External 3.0USB 1TB Hard Disk (HFS+ File System) can be identified with the Black color, then I have another with the same characteristic to copy my recovered files with the Gray color. On Ubuntu I can't write using HFS+ then I formatted the HDD Destiny/Gray like Ext4 File System.

I can see the tree and the files in Ubuntu, but in macOS not (using Finder)!!!

I can't see my files on macOS Sierra my Hard Disk have HFS+ File System (originally used by macOS).

I can't see my files on **macOS Sierra**

Strangely I can see using Ubuntu the files I can see using **Ubuntu** the Files of external <code>HFS+</code> HDD

Now I'm using ddrescue on Linux Ubuntu 17.04. but it is possible to use this command on macOS Sierra too!

But my machine (MacBook Air) only has two 3.0USB ports. Like I haven't Ubuntu installed, I need a Live Version, using a Stick (I have a 3.0USB 16GB Stick). But the disks Source/Black and Destiny/Gray are External, then I need a USB Hub.

Here my Scenario to recover my files.enter image description here

Then to use a Ubuntu Live through a external 3.0USB Stick I need to use a USB hub, only I have a 2.0USB Hub with Silver color, and the speed allowed on 2.0USB is sensible lower than 3.0USB.

This ddrescue can take months using 2.0USB Hub to connect the Two HDD's in recover process.


Can I to do this process on macOS Sierra side (with its SSD HDD - only I have 15GB free space), using the two 3.0USB ports to connect the Source/Black and Destiny/Gray (using HFS+ File System) HDD's to improve the speed?.

Can be the results different?

In the dd command is recommended to unmount the hard disk's, is needed in ddrescue and dd_rescue too?


I-m trying to recover my data on macOS side in this questions:

recover Files from corrupted External USB HD, macOS Sierra

using gpt : unable to open device ..': Resource busy

  • If your disks have different geometries you can't just copy the raw images with dd or ddrescue. Format the destination disk, mount both disks, and copy your files with rsync or dump / restore. Also when you're using an USB hub the entire traffic through the hub is limited to the speed of the port your hub is plugged to. Find a machine with two USB 3 ports, preferably on different controllers, and do the transfer there. Otherwise it will take forever and a day. – Satō Katsura Oct 6 '17 at 6:44
  • Then I can't use HFS+ in one side and Ext4 in another. Then the best option is to use ddrescue on macOS side because I will be using the machine's internal HDD (with Sierra) and I can use freely the two 3.0USB ports. But why I can't see the files on macOS side like Ubuntu (without size)? – Chepe Questn Oct 6 '17 at 6:53
  • Read this carefully: you can't use ddrescue if your disks have different geometries. You can't see your files because what you're doing doesn't make sense. – Satō Katsura Oct 6 '17 at 7:05
  • @SatōKatsura The damaged disk has HFS+ originally, but in macOS Sierra I can't see the files to be recovered, but in Ubuntu I can see the files (still ubuntu is Ext4 based on). Then to use dd/ddrescue I will need to reformat the Destiny HDD like HFS+ again to have Source and Destiny in the same File System. The problem is Ubuntu don't let me write on HFS+ HDD. – Chepe Questn Oct 6 '17 at 7:13

I would not use ddrescue but testdisk. You can get testdisk for Mac OS X here: http://www.cgsecurity.org/wiki/TestDisk

Then all you need is to hook up your two disks, open the Terminal (/Applications/Utilities/Terminal.app), change directory into your "Destiny" volume. You can see the name of the volume in finder, locate it under /Volumes: perform the following in Terminal: ls /Volumes and locate the name of the volume. Next, change directory: cd '/Volumes/<name_of_volume>', then you run testdisk (you will have to place it somewhere, assuming it is on your desktop in folder testdisk), ~/Desktop/testdisk/testdisk, make sure you select the correct source and target drives and let it run over the night.

See http://www.cgsecurity.org/wiki/TestDisk_Step_By_Step for exact steps in testdisk.

| improve this answer | |
  • Here my result with TestDisk and PhotoRec askubuntu.com/questions/955325/… – Chepe Questn Oct 6 '17 at 7:37
  • It looks like your drive is in a dire state, I would say, almost unrecoverable without specialist tools. In the ubuntu thread, you claim to be able to get a directory tree, fine, can you copy paste a directory from that to another drive ? I doubt it. – thecarpy Oct 6 '17 at 21:06
  • Thank you, have you some name for specialist tools recommended for this situation? – Chepe Questn Oct 7 '17 at 3:48
  • @thecarpy As its name indicates, 'testdisk' has never been reliable, serious and as professional as other tools in handling data recovery operations. – user6039980 Oct 25 '17 at 14:13
  • @ChepeQuestn Even if testdisk is faster than GNU ddrescue, it doesn't mean it is better. A fast tool is not essentially a better tool. You must think about the quality of produced results, not the performance itself. – user6039980 Oct 25 '17 at 14:18

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.