Eu sugiro que você execute o fdisk na partição. Já fiz isso antes e tive sucesso com erros semelhantes.
% bl0ck_qu0te%Extraído da sugestão aqui: link
NOTA: Isso apagará sua tabela de partições
ao criar a partição após o erro aparecer
error creating partition: helper exited with exit code 1: In part_add_partition: device_file=/dev/sda, start=307198163968, size=118189196288, type=0x83
Entering MS-DOS parser (offset=0, size=640135028736)
MSDOS_MAGIC found
looking at part 0 (offset 32256, size 307197725184, type 0x07)
new part entry
looking at part 1 (offset 307198163968, size 332936512512, type 0x0f)
Entering MS-DOS extended parser (offset=307198163968, size=332936512512)
readfrom = 307198163968
MSDOS_MAGIC found
readfrom = 586446013440
MSDOS_MAGIC found
readfrom = 307205982720
No MSDOS_MAGIC found
Exiting MS-DOS extended parser
looking at part 2 (offset 0, size 0, type 0x00)
new part entry
looking at part 3 (offset 0, size 0, type 0x00)
new part entry
Exiting MS-DOS parser
MSDOS partition table detected
containing partition table scheme = 1
got it
Error: Invalid partition table on /dev/sda -- wrong signature 0.
ped_disk_new() failed
Por favor, consulte Link link para detalhes sobre o particionamento