Seagate 4TB USB drives

[expeditionist]

Hi guys

I'm scratching my head here trying to understand something and need some help please.

I've got 2 x Seagate 4TB external USB HDD's on my system, both with a single 3.64TB partition.

Now here's the mystery, both MiniTool Partition Wizard Pro and Windows Disk Management showed the partition style as MBR and not GPT. Everything I've read tells me that a partition size above 2.2TB is not possible with MBR so what's going on? They came out of the box as MBR 4TB I believe, so how is that even possible?

Please see the screen print at https://goo.gl/pmVbAu - (disks T and U and U has since been changed as per below...)

Furthermore, I've used MiniTool Partition Wizard Pro to convert one of the disks to GPT, but now I observe that using MiniTool Partition Wizard Pro to convert to GPT means that the disks are missing the usual 128MB MSR hidden partition that usually comes with GPT. What will be the consequences of having no 128MB MSR?

Thanks

 

[Rookie_MIB]

There are two types of drives, the 512byte sector drives (normal/old drives) and the advanced format drives which use 4kb sector sizes.

With the 512byte sectors and the 32bit MBR limitation on the number of sectors, that means a maximum of 2.2TB per drive. With the 4kb sectors and the 32bit MBR sector limitation that means a total capacity of 16TB or so.

 

[expeditionist]

Thanks, that make sense then. So many places on the web tell you that MBR can't be more than 2.2TB. That simply isn't true then!

What about the other part of my question please? When MiniTool Partition Wizard Pro converts a disk from MBR to GPT, you end up with a converted disk that is missing the usual 128MB MSR hidden partition that usually comes with GPT. What is that 128MB partition usually used for and what will be the consequences of not having it?

Thanks

 

[Rookie_MIB]

The MSR is a small partition that is usually needed if the drive is a 'bootable' drive, but if it's a secondary drive or removable drive, it's not needed. If you delete it, and then decide to make the drive a bootable drive, the process of installing will re-create those MSR partitions.

So - don't worry about it.