3TB USB HD Format Question

[Stereodude]

Does anyone know how the 3TB USB HDs are formatted?

I have 2 USB 3.0 Seagates 3TB drives. They show up as a single 3TB partition (base 10). They are not GPT, but MBR partitions. My rough understanding is that is possible because they have 4k sectors, not 512byte sectors they can exceed 2TB without needing to be GPT. However, Windows 7 won't let me format a MBR partition that's >2TB and can't seem to duplicate the factory format on the disks. Is there a trick am I missing?

 

[ddrueding]

I thing all your understanding is correct. But I have always just formatted them as GPT, so I can't help you on that. Is there a reason you want MBR?

 

[Stereodude]

Mainly so they're readable by XP machines. I accidentally destroyed the factory format of one of them while trying to wipe it clean / test all the sectors (full format). However, I was able to use Clonezilla to mirror the one that was still factory fresh to the one where I messed up the format. It didn't have any issues cloning the drive. I would like to know how to clean format one of them with the same setup as the factory. I bet a gparted liveCD can probably do it...

 

[ddrueding]

Yeah, I haven't tried it, but I'd bet most 3rd party disk tools could do it.

 

[Stereodude]

Either my Google-fu is weak or almost no one else is attempting to dig into making MBR partitions >2TB because of the larger than 512byte sectors that you get as a side effect of the USB interface. I've seen a few posts around the web with people asking how to make 'em, but the replies are mostly just people insisting there's a 2TB limit or explanations of how to use GPT instead.

I guess I will try the latest versions of gparted and partedmagic and see what happens. If I mess things up I can always restore the backup image I made.

 

[ddrueding]

That should be a really small image if the drive is empty

 

[mubs]

Wouldn't the mfr have a low-level format utility that will put it back to factory format?

 

[Clocker]

However, I was able to use Clonezilla to mirror the one that was still factory fresh to the one where I messed up the format.

Very clever!

 

[Stereodude]

Wouldn't the mfr have a low-level format utility that will put it back to factory format?

Based on what I've seen posted around, apparently the answer is no.

 

[Stereodude]

So I used the latest Gparted (0.14.1-6-i486) and had no issues deleting the existing partition, creating a new MS-DOS partition table (not a GPT partition table) and then making a single NTFS partition that took up the entire drive.

 

[mubs]

Based on what I've seen posted around, apparently the answer is no.

That's utterly incomprehensible.

Anyway, I'm glad GParted worked for you. Good to know.