[CentOS] centos 6.2; mount 6TB OSX formatted FW

Fri Apr 20 14:52:28 UTC 2012
Lamar Owen <lowen at pari.edu>

On Thursday, April 19, 2012 02:49:41 PM aurfalien wrote:
> Trying to mount an FW800 6TB volumes.

> The logs say; 
> cannot find hfs+ superblock


(it's Friday: and now I'm channelling Michael J Fox in Teen Wolf pronouncing that name... sorry).

My first question is: which HFS+ filesystem module are you using, since CentOS 6 by default does not include HFS+ capability?  

(See: https://docs.redhat.com/docs/en-US/Red_Hat_Enterprise_Linux/6/html/Migration_Planning_Guide/sect-Migration_Guide-Package_Changes-Driver_Changes.html )

There are pretty significant issues with the weakly maintained in-kernel HFS+ filesystem drivers (probably the reason upstream isn't shipping HFS+ enabled by default): see:

Namely, due to a 32-bit data type being used the in-kernel driver can (and will) corrupt any >2TB volume when you try to write above the 2TB 'boundary' even when used in a 64-bit kernel.

Now, assuming that you're not already using it, have you tried the trial download of Paragon's commercial HFS+ filesystem?  See:
http://www.paragon-software.com/home/ntfs-linux-per/ for the free to use Express edition.  (I know that says ntfs in the URL; the HFS+ and NTFS filesystems are a bundle). 

I've done significant data migrations and interchange with HFS+ volumes and various Macs, and the in-kernel HFS+ filesystem is very flakey.  I've not had those issues with the Paragon HFS+ filesystem, or for that matter the NTFS filesystem driver that comes in the bundle.  The Paragon documentation states that there is no limit on filesystem size imposed by this driver; just limits imposed by the kernel or by the NTFS/HFS+ systems themselves.  I've not personally tried a >2TB HFS+ filesystem with this driver, so I'd test it well before using in production.

This driver includes read/write access to HFS+ Journaled volumes; the in-kernel driver is read-only for HFS+ Journaled volumes.

The Professional version of the driver (available with a free trial period for testing) includes diags, including an fsck and mkfs for both filesystems.

Now, to help troubleshoot this a little, you may want to get gdisk from EPEL to see how that thing is partitioned.