gparted cannot get rid of 30kb head partition of an HFS disk formated in Mac OS X

[komputes]

Ubuntu 9.04
linux 2.6.28-11-generic
gparted 0.4.3-0ubuntu1

gparted cannot get rid of 30kb head partition of an HFS disk formated in Mac OS X:

GParted 0.4.3

Libparted 1.8.8
Delete /dev/sdb1 (unknown, 31.50 KiB) from /dev/sdb 00:00:10 ( ERROR )

calibrate /dev/sdb1 00:00:00 ( SUCCESS )

path: /dev/sdb1
start: 1
end: 63
size: 63 (31.50 KiB)
delete partition 00:00:10 ( ERROR )
libparted messages ( INFO )

Partition map has no partition map entry!

========================================

[komputes (komputes)]

fdisk does not show a (null) partition there either. Logically, there should still be a way to wipe the entire disk.

[Jan Claeys (janc)]

(By default) Mac OS X uses GPT-partitioning instead of MSDOS-partitioning. I think fdisk doesn't know about GPT partitioning and thus only sees the MSDOS compatibility MBR that GPT includes. If you want to wipe the disk completely, you can write a new "disk label" (partitioning format) to the disk (this option is in the Device menu).

To find what might cause your problem, can you please attach the output of the following two commands (before writing the new partition table!):
sudo parted /dev/sdb print
sudo fdisk -l /dev/sdb

[komputes (komputes)]

Sorry for the delayed response, but I did not have a mac around me after having eported this bug. I just formated a USB disk HSF plus on a friends mac and here is the info you asked for:

/dev/sdc3 on /media/Kingston USB key type hfsplus (rw,nosuid,nodev,uhelper=devkit)

komputes@karmic:~$ sudo parted /dev/sdc print
Model: Kingston DataTraveler 2.0 (scsi)
Disk /dev/sdc: 8074MB
Sector size (logical/physical): 512B/512B
Partition Table: mac

Number Start End Size File system Name Flags
 1 512B 32.8kB 32.3kB Apple
 3 134MB 8074MB 7940MB hfs+ Untitled

komputes@karmic:~$ sudo fdisk -l /dev/sdc

Disk /dev/sdc: 8074 MB, 8074035200 bytes
249 heads, 62 sectors/track, 1021 cylinders
Units = cylinders of 15438 * 512 = 7904256 bytes
Disk identifier: 0x00000000

Disk /dev/sdc doesn't contain a valid partition table

[Nicolás Alvarez (nicolas-alvarez)]

That first partition *is* the partition table (aka partition map), that's why you can't remove it. "The Apple partition map is unusual in that it defines itself as one of the partitions on the disk."

If you delete it, you get "Partition map has no partition map entry!", which means the partition map lacks an entry referring to itself as the first partition (because you deleted it).

I just toggled the bootable flag of it using the command-line parted tool, and now it keeps saying "Partition map has no partition map entry!" and not letting me toggle it back :/