3TB hard drive detecing as 800gb on Windows 10

[complexsoul]

I have a 3TB Toshiba hard drive that I previously used for my OMNINAS K20. I now need to use this drive to clonezilla one of my 1TB drives that is slowly dying. However when I clonezilla it, sees the 3TB drive as 800gb instead. So then hooked it up to my laptop and under disk management, it only sees it as 800gb too. When I view the disk under properties though, it sees the drive as 800gb free and 1.2gb used so at the minimum,

I am running windows 10 64-bit OS andI know there's some issue with seeing it as a 3TB drive on windows but I should at least be able to format the drive to 2TB right? I am thinking that the OMNINAS program must have locked part of the drive away but I'm not sure if that's the case and if it is, how to get rid of it.

Any ideas? Thanks.


Update:
Thanks for the response but unfortunately I haven't had any luck yet. The disk is already converted to a GPT but still shows only the 800gb partition. Did the checkdisk one as well, no dice. I am currently trying to use a tool call minitool partition to see if I can recover any lost partition though it's taking a while for the scan.

Update:
Cleaned using a partitioning tool got it work.

 

[mips42]

I would agree that the OmniNAS likely has / had some special formatting. As to how to get rid of it, there are 3 ways that I know of:
1) Use a program like EaseUS Partition manager to delete the hidden partitions;
2) use windows built in tool DiskPart (command line tool);
3) connect the drive to a Linux system and use GRUB

I've listed these in ease-of-use order.

Good luck!

 

[ko888]

What is the partition style on that 3TB HDD? Is it MBR (Master Boot Record) or GPT (GUID Partition Table) or something else? A single partition over 2TB in size requires using GPT partition style.

 

[Guest]

The 2TB limit is because the disk is MBR instead of GPT, or something like that. Open disk manager, choose your 3TB drive (the box on the right of the partition graphic), and choose "convert to GPT". This will destroy all data on the 3TB drive, btw. But you will have a 3TB drive.

If you see other options, choose NTFS, biggest size page table, or the defaults, and you'll be fine.

 

[Guest]

You have to right click the disk in disk manager, btw.