The classic case has occurred... Still had an external hard drive with recordings from an old satellite receiver, which was formatted in Ext3/4. Since the receiver is out of order and I could mount the drive only with my Linux machine, I copied the important recordings over to my Mac because this is my media server. Then the hard disk reformatted, under MacOS with HFS+. (Fast mode and kept in MBR.) But now realized that I had forgotten to copy a folder (approx. 50 GB)! 
It's a 2TB HDD with only a few MB new data on it after reformatting.
Now the big question, is there still a chance to recover the data? Does anyone have experience with this? Am grateful for any help!
there is testdisk and ddrescue to recover data, if that helps.
1 Like
In addition to testdisk and ddrescue mentioned above, I have had success with UFS Explorer. Some people recommend making a clone copy of the disk using the dd command just in case something goes wrong with the rescue effort.
1 Like