One 2TB Seagate hardrive showing up as 2 drives

[Destroyful]

Both identical drives that display they each have 500gb space available totalling 1tb. However, the whole drive is 2tb so 1tb is just 'missing' and this one drive is separated into two drives. I need to use this drive to back up my mac.

 

[nicho]

View attachment 887685

Both identical drives that display they each have 500gb space available totalling 1tb. However, the whole drive is 2tb so 1tb is just 'missing' and this one drive is separated into two drives. I need to use this drive to back up my mac.

Possible that the other 1tb is in a third partition not readable on a mac. Click on "view" at the top and select
show all devices" rather than "show volumes".

 

[||\||]

View attachment 887685

Both identical drives that display they each have 500gb space available totalling 1tb. However, the whole drive is 2tb so 1tb is just 'missing' and this one drive is separated into two drives. I need to use this drive to back up my mac.

IIRC, those don’t look like typical Seagate naming conventions. It looks like someone partition the drive and maybe 1TB is in some exotic format that cannot be read.

 

[Fishrrman]

1. In disk utility (see your pic above), go to the "view" menu and choose "show all devices".

2. NOW look at the representation for the Seagate drive. You should see a "top line" which represents the physical drive itself.

3. Click this, then click the erase button. Choose Mac OS extended with journaling enabled, GUID partition format.

4. Erase the drive and you should have ONE logical volume of about 1tb.

WARNING WARNING WARNING
Doing this will DESTROY any data that is already on the drive!
There's nothing on it you want to save, right...?

 

[jeyf]

seem to recall some Seagate external drives were formatted from the factory kinda odd.
see if you can wipe the whole drive & re format