HFS+ Partition recognised as FAT (will not mount)

[yfyfyf]

hi all, here is a tricky one. I have been using this HFS+ partition under Windows Vista/7 (with MacDrive) for a very long time. At first the partition was store on an external HDD, and at the time it was readable by both Windows and OSX.

 

One year ago I have relocated the whole partition (as a clone copy) to an internal HDD. and have been using it under a Win7 environment for almost a year with no problem.

 

Recently I put up a new 10.6 system in this old box and under Win7 I am able to mount and access(RW) the partition but I can't say the same for OSX. I am not able to mount the HFS+ partition at all, but I have no problems with the other partitions with both Mounting and RW under both platforms. I have the strangest feeling its a fault to do with the partition.

 

Gparted also recognised this as a HFS+ partition with no faults. And Here is a print out from diskutil:

 

/dev/disk0
  #:					   TYPE NAME					SIZE	   IDENTIFIER
  0:	  GUID_partition_scheme						*203.9 GB   disk0
  1:						EFI						 209.7 MB   disk0s1
  2:				  Apple_HFS MacOSX				  203.6 GB   disk0s2
/dev/disk1
  #:					   TYPE NAME					SIZE	   IDENTIFIER
  0:	 FDisk_partition_scheme						*122.9 GB   disk1
  1:			   Windows_NTFS System Reserved		 104.9 MB   disk1s1
  2:			   Windows_NTFS Win7					122.8 GB   disk1s2
/dev/disk2
  #:					   TYPE NAME					SIZE	   IDENTIFIER
  0:	  GUID_partition_scheme						*2.0 TB	 disk2
  1:	   Microsoft Basic Data						 1.0 TB	 disk2s1
  2:	   Microsoft Basic Data storage D2			  203.9 GB   disk2s2
  3:				  Apple_HFS Samples				 512.7 GB   disk2s5
  4:						EFI						 209.7 MB   disk2s4
/dev/disk3
  #:					   TYPE NAME					SIZE	   IDENTIFIER
  0:	 Apple_partition_scheme						*1.0 TB	 disk3
  1:		Apple_partition_map						 32.3 KB	disk3s1
  2:				  Apple_HFS PLUGS				   1.0 TB	 disk3s3

 

the problematic partition is disk2s1

 

 

Device Identifier:		disk2s1
  Device Node:			  /dev/disk2s1
  Part Of Whole:			disk2
  Device / Media Name:	  Untitled 1

  Volume Name:			  
  Escaped with Unicode:	 

  Mounted:				  No

  File System:			  MS-DOS
  Type:					 msdos
  Name:					 MS-DOS (FAT)

  Partition Type:		   Microsoft Basic Data
  Bootable:				 Is bootable
  Media Type:			   Generic
  Protocol:				 SATA
  SMART Status:			 Verified

  Total Size:			   1.0 TB (1000203091968 Bytes) (exactly 1953521664 512-Byte-Blocks)
  Volume Free Space:		0 B (0 Bytes) (exactly 0 512-Byte-Blocks)

  Read-Only Media:		  No
  Read-Only Volume:		 Not applicable (not mounted)
  Ejectable:				No

  Whole:					No
  Internal:				 Yes

 

whoever can sort this out will be an absolute legend!!

 

YF

 

oh if it helps I am using VIA VT8237A chipset and the device is run on a SATA controller JMicron JMB363

 

other partitions mounts with no issues under OSX.... although Disk2s2 should say NTFS.....

[srs5694]

It's almost certainly just a matter of having an inappropriate partition type code set. I think that OS X's standard "gpt" text-mode utility can fix this, but I don't recall the exact syntax offhand. You could instead use my GPT fdisk (gdisk) to do the job. It'd go something like this:

 

1. Launch the program on your disk by typing "sudo gdisk /dev/disk2"
   
2. Type "p" to view your partitions and verify you're working on the correct disk.
   
3. Type "t" to change a type code. Enter the partition number and "af00" for the partition type code.
   
4. Type "p" again to review the change and ensure you changed the correct partition.
   
5. Type "w" to write the changes to disk. Answer "y" to verify that you really want to save changes.
   

 

One caveat: I vaguely recall hearing that MacDrive does weird things with partition type codes; you might find that it keeps changing it back or that it won't be able to access the drive after you set the code correctly. I don't recall exactly what the problem is or if there's a fix or workaround, though; it might be something minor or easily fixed.