How to mount Core Storage volume under Linux (or force conversion on unrevertible volume)

core-storagediskutilhfs+mount

I tried to mount HFS+ partition in Linux today, but I had problem with

hfsplus: unable to find HFS+ superblock

I've found later that this partition is in fact Core Storage container for the logical volume, what could mean I should at least know corrected offset of the real logical volume on this partition.

I tried to follow advices seen in plenty of places to revert the volume using diskutil cs revert UUID, however my problem is that I see:

Logical Volume C4FE8...
-----------------------------------------------------
[...]
Revertible:      No
[...]

Logical Volume Family above this has all encryption related fields set to No/None. However I cannot find a way how to have this volume revertible.

Because it's only 300 GB of data on 1TB drive, I've managed to shrink it. The idea I have is to create empty partition of the same size as the volume and the copy it using dd. Then I would have pure HFS+ partition probably mountable under Linux. However gpt in recovery doesn't allow me to add next partition to disk0 saying "resource is busy". Graphical utility seem to have some bug and I cannot confirm new partition (in recovery mode as I don't know the password to superuser account).

Now, does anyone manage to mount Core Storage volume at least read-only under Linux?
Or maybe someone found the way how to make this Core Storage volume revertible?

Best Answer

I don't know if it's possible to remove CoreStorage entirely once a disk's been converted, but it is possible to mount the HFS volumes inside (provided they are not encrypted - if so, you'll also need to use libfvde).