A partition copied with cat can't be mounted

Question

OK, I asked it in AskDifferent, but seems that apple folks don't get the idea that everything is file in unix.

Well some days ago my mac got broken, I had an Ubuntu on it and booted through it, first thing I did I copied mac partition to an external hard partition, something like this:

cat /dev/sda2 > /dev/sdc2

I was able to mount the sda2 partition in Ubuntu with hfsprogs, but I wasn't able to mount /dev/sdc2, I made a diff on two devices (with cmp) and they were just identical, now I erase sda2 and installed Yosemite again but I can't mount sdc2 even on mac (here it's disk2s2).

When I try to mount, verify or repair it, I get this error:

Invalid node structure

(this is the same error I got in Ubuntu for this partition), it's really weird cause I'm sure this partition is identical to the real one (and I was able to mount the real one in Ubuntu) I tried fixing it with DiskWarrior 5, it did its job without any error, but it didn't fix it, I also used fsck_hfs both in Ubuntu and OSX.

Any idea how can I mount this cloned partition in Ubuntu? As I compared these two devices after cloning and they were identical I guess it must be some information in partition table or something like that.

In AskDifferent they just keep saying that I should've use dd, ok, maybe I should've use dd, but I can't change the tool I used in past, my current problem is to recover this partition.