Mac OS X 10.8-10.9 - Disk is unreadable

[Kevyn-Alexandre Paré]

Hi,

First time that I try exFat from Linux (Ubuntu 12.04):
So First here what I have done to install it:

sudo apt-add-repository ppa:relan/exfat
sudo apt-get update
sudo apt-get install fuse-exfat exfat-utils

Here what I have done to create an exFat partition from 15G usbkey:

sudo fdisk -l /dev/sdd

WARNING: GPT (GUID Partition Table) detected on '/dev/sdd'! The util
fdisk doesn't support GPT. Use GNU Parted.


Disk /dev/sdd: 15.6 GB, 15610576896 bytes
139 heads, 36 sectors/track, 6093 cylinders, total 30489408 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x0734a21a

Device Boot Start End Blocks Id System
/dev/sdd1 2048 30489407 15243680 7 HPFS/NTFS/exFAT
knight@knight:$
knight@knight:$
knight@knight:$ sudo mkfs.exfat -n "KEY" /dev/sdd1
mkexfatfs 1.0.1
Creating... done.
Flushing... done.
File system created successfully.
knight@knight:$ sudo fsck.exfat /dev/sdd1
exfatfsck 1.0.1
Checking file system on /dev/sdd1.
File system version 1.0
Sector size 512 bytes
Cluster size 32 KB
Volume size 15 GB
Used space 2144 KB
Available space 15 GB
Totally 0 directories and 0 files.
File system checking finished. No errors found.
knight@knight:$
knight@knight:$ sudo mount /dev/sdd1 /media/boot
FUSE exfat 1.0.1
knight@knight:$ ls /media/boot/
knight@knight:$ sudo umount /dev/sdd1


Then when connecting the key to MAC a pop up says that the key is unreadable?

What's wrong from my procedure?

thx,

-KA

[Andrew Nayenko]

Hi,

> WARNING: GPT (GUID Partition Table) detected on '/dev/sdd'! The util
> fdisk doesn't support GPT. Use GNU Parted.

Does it work with DOS-type partition table?

--
Andrew Nayenko <res...@gmail.com>

[Kevyn-Alexandre Paré]

On Wed, Feb 12, 2014 at 3:48 AM, Andrew Nayenko <res...@gmail.com> wrote:
> Hi,
>
>> WARNING: GPT (GUID Partition Table) detected on '/dev/sdd'! The util
>> fdisk doesn't support GPT. Use GNU Parted.
>
> Does it work with DOS-type partition table?
>

Just to be sure you mean that I should select something else then 7 -
HPFS/NTFS/exFAT in fdisk. What do you suggest?
0 Empty 24 NEC DOS 81 Minix / old Lin bf Solaris
1 FAT12 27 Hidden NTFS Win 82 Linux swap / So c1 DRDOS/sec (FAT-
2 XENIX root 39 Plan 9 83 Linux c4 DRDOS/sec (FAT-
3 XENIX usr 3c PartitionMagic 84 OS/2 hidden C: c6 DRDOS/sec (FAT-
4 FAT16 <32M 40 Venix 80286 85 Linux extended c7 Syrinx
5 Extended 41 PPC PReP Boot 86 NTFS volume set da Non-FS data
6 FAT16 42 SFS 87 NTFS volume set db CP/M / CTOS / .
7 HPFS/NTFS/exFAT 4d QNX4.x 88 Linux plaintext de Dell Utility
8 AIX 4e QNX4.x 2nd part 8e Linux LVM df BootIt
9 AIX bootable 4f QNX4.x 3rd part 93 Amoeba e1 DOS access
a OS/2 Boot Manag 50 OnTrack DM 94 Amoeba BBT e3 DOS R/O
b W95 FAT32 51 OnTrack DM6 Aux 9f BSD/OS e4 SpeedStor
c W95 FAT32 (LBA) 52 CP/M a0 IBM Thinkpad hi eb BeOS fs
e W95 FAT16 (LBA) 53 OnTrack DM6 Aux a5 FreeBSD ee GPT
f W95 Ext'd (LBA) 54 OnTrackDM6 a6 OpenBSD ef EFI (FAT-12/16/
10 OPUS 55 EZ-Drive a7 NeXTSTEP f0 Linux/PA-RISC b
11 Hidden FAT12 56 Golden Bow a8 Darwin UFS f1 SpeedStor
12 Compaq diagnost 5c Priam Edisk a9 NetBSD f4 SpeedStor
14 Hidden FAT16 <3 61 SpeedStor ab Darwin boot f2 DOS secondary
16 Hidden FAT16 63 GNU HURD or Sys af HFS / HFS+ fb VMware VMFS
17 Hidden HPFS/NTF 64 Novell Netware b7 BSDI fs fc VMware VMKCORE
18 AST SmartSleep 65 Novell Netware b8 BSDI swap fd Linux raid auto
1b Hidden W95 FAT3 70 DiskSecure Mult bb Boot Wizard hid fe LANstep
1c Hidden W95 FAT3 75 PC/IX be Solaris boot ff BBT
1e Hidden W95 FAT1 80 Old Minix

our do you mean:
Command action
a toggle a bootable flag
b edit bsd disklabel
c toggle the dos compatibility flag
d delete a partition
l list known partition types
m print this menu
n add a new partition
o create a new empty DOS partition table

the "o" option?


thx

-KA

[Kevyn-Alexandre Paré]

Reading more about the warning I found that the GPT is not supported
with fdisk and that I should use parted.

So from that I try to only use parted for removing the GPT and replace
it with msdos:

sudo dd if=/dev/zero of=/dev/sdd bs=1024 count=1024
1024+0 records in
1024+0 records out
1048576 bytes (1.0 MB) copied, 0.239017 s, 4.4 MB/s
knight@knight:$ sudo parted -s /dev/sdd mklabel msdos;echo $?
0
knight@knight:$ sudo fdisk -l /dev/sdd

Disk /dev/sdd: 15.6 GB, 15610576896 bytes

64 heads, 32 sectors/track, 14887 cylinders, total 30489408 sectors

Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes

Disk identifier: 0x000924f1

Device Boot Start End Blocks Id System

Then I repeat my previous step and was able to use the key on mac/windows.

[1] Is there other way to pass from GPT to msdos then using parted?
[2] Is it possible to use GPT and exFat? if yes what tools are needed?

thx,

-KA

[Andrew Nayenko]

> So from that I try to only use parted for removing the GPT and replace
> it with msdos

> Then I repeat my previous step and was able to use the key on mac/windows.

Yes, that's exactly what I meant.

> [2] Is it possible to use GPT and exFat? if yes what tools are needed?

I'm sure it is possible. Try setting exFAT partition GUID to
EBD0A0A2-B9E5-4433-87C0-68B6B72699C7
See https://en.wikipedia.org/wiki/Basic_Data_Partition

[Kevyn-Alexandre Paré]

Andrew,

On Thu, Feb 13, 2014 at 3:25 AM, Andrew Nayenko <res...@gmail.com> wrote:
>> So from that I try to only use parted for removing the GPT and replace
>> it with msdos
>
>> Then I repeat my previous step and was able to use the key on mac/windows.
>
> Yes, that's exactly what I meant.

perfect, so using fdisk should maybe remove from my tools list for
exfat and maybe become my principal tool ;)

>
>> [2] Is it possible to use GPT and exFat? if yes what tools are needed?
>
> I'm sure it is possible. Try setting exFAT partition GUID to
> EBD0A0A2-B9E5-4433-87C0-68B6B72699C7
> See https://en.wikipedia.org/wiki/Basic_Data_Partition

After reading back my question it sound obvious since the drive came
with GPT and exFat. But what I should have ask is:
Is it well supported with the source code for exfat or should I always
use by default the msdos setting?

Will read more about parted and your link thx

-KA

[Andrew Nayenko]

> After reading back my question it sound obvious since the drive came
> with GPT and exFat. But what I should have ask is:
> Is it well supported with the source code for exfat or should I always
> use by default the msdos setting?

fuse-exfat and exfat-utils know nothing about partition table format.
It's operating system's duty to parse partition table and create
special files (/dev/sda1, /dev/sda2, etc.) representing those
partitions. So both GPT and DOS partitioning should work equally well.

But I didn't test disks with GPT on my own and I don't have a Mac near
by right now. Keep us informed your experiments.

--
Andrew Nayenko <res...@gmail.com>

[Kevyn-Alexandre Paré]

Andrew,

On Sat, Feb 15, 2014 at 4:39 AM, Andrew Nayenko <res...@gmail.com> wrote:
>> After reading back my question it sound obvious since the drive came
>> with GPT and exFat. But what I should have ask is:
>> Is it well supported with the source code for exfat or should I always
>> use by default the msdos setting?
>
> fuse-exfat and exfat-utils know nothing about partition table format.
> It's operating system's duty to parse partition table and create
> special files (/dev/sda1, /dev/sda2, etc.) representing those
> partitions. So both GPT and DOS partitioning should work equally well.
>

Thx for the clarification

> But I didn't test disks with GPT on my own and I don't have a Mac near
> by right now. Keep us informed your experiments.

I will keep you updated. I have mac with OS X 10.7, 10.8 and 10.9 that
I can test exfat. For now I have tested it from Ubuntu 12.04 create SD
then try it on 10.8.

thx,

-KA