Comment 4 for bug 889928

I see the same issue, I guess. I copied the main data partition (250 gb) from a friend's broken mac using "ddrescue /dev/sdc2 rescued.img rescued.log" and tried to mount it with "mount -o loop,ro rescued.img /mnt"

In Ubuntu 12.04 as well as 14.04 I get "invalid secondary volume header" and "unable to find HFS+ superblock".
I also tried with "losetup" manually as suggested by some forum entry but without success.
I also tried with offset and size, but it does not help because the file size of the image is equal to the original partition size.

# parted /dev/sdc unit B print
Modell: Hitachi HTS545025B9SA02 (scsi)
Festplatte /dev/sdc: 250059350016B
Sektorgröße (logisch/physisch): 512B/512B
Partitionstabelle: gpt
Nummer Anfang Ende Größe Dateisystem Name Flags
 1 20480B 209735679B 209715200B fat32 EFI System Partition boot
 2 209735680B 249409327103B 249199591424B hfs+ Macintosh HD
 3 249409327104B 250059329535B 650002432B hfs+ Recovery HD

# file rescued.img
Macintosh HFS Extended version 4 data (mounted) last mounted by: 'HFSJ', created Thu Jun 21 12:24:20 2012, last modified: Sat May 16 20:50:35 2015, last checked: Thu Jun 21 19:24:20 2012, block size: 4096, number of blocks: 60839744, free blocks: 14124774

... but in Ubuntu 10.04 the mount works just fine!