hard drive size

Tech198

macrumors G5
Original poster
Mar 21, 2011
13,976
1,643
Australia, Perth
Hi all..

When doing a zero disk on a 4TB hard drive, I'm attaching it via USB-to-sata, since the drive is an internal 4TB, and i stand a preiity good chance of it being about the same as SATA 3.0 (6Gigbps vs 5Gbps for USB 3.0)

In any case, after i plug this in to my mac and run up terminal it only reports the drive size total as 1.8TB not 4TB


DU reports the same, so when i zerodisk will it only do 1.8TB or do the whole drive (assuming usb doesn't decide to disconnect) ?

The drive DID come from a NAS formatted as EX4, but i would think OS X would be able to handle it.

ANy suggestions ?
 

hallux

macrumors 68030
Apr 25, 2012
2,774
485
On the partition tab (available when the disk is selected, not the partition) select Options below the list/diagram of how the drive will be split. On there, make sure it's set for GUID Partition Table, MBR may not handle drives over 2 TB.

This WILL erase all data on the drive but that sounds like the ultimate goal anyway.
 

Tech198

macrumors G5
Original poster
Mar 21, 2011
13,976
1,643
Australia, Perth
Yes, i do want to erase it, but i don't want to partition it.... This is why i'm wanting to use Terminal, as I just want to zerodisk the entire drive...

Maybe OS X doesn't support EXT4 ? *shrugs*

Although, just for the sake of this, i tried zerodisk'ing a few minutes just to blank the partition table (thinking this might have been why OS X only say 1.8TB, but even after cancelling quitting Termainal, and going back to DU, it still saw only 1.8TB)

Although, i am using Activekill disk with drive connected internally to "shared" PC, although the reason why i wanted to do this from laptop, was mainly because the PC was used by someone...

However on the PC, Activekill does see 4TB.. it will take approx 13 hours, after of which i will hook it up again via usb dongle on Mac, and see if the blan dirve would be recognized as 4TB..

However, this would be preferred, i'm looking at why OS X would see the full capacity...
 

illusionx

macrumors 6502
Jul 4, 2014
326
0
Brossard, QC
hard drive size

Why do you not want to repartition it as 1 portion ? Since this drive came from a NAS. It is quite possible that there is a unreadable partition in OS X.
 

Tech198

macrumors G5
Original poster
Mar 21, 2011
13,976
1,643
Australia, Perth
Why do you not want to repartition it as 1 portion ? Since this drive came from a NAS. It is quite possible that there is a unreadable partition in OS X.
ok, that would probably make sense, but i was surprised even blanking partition table, it didn't see 4TB still..

I do want to use it as 1 portion since i am going to stick it back in the NAS, however i want to use OS X to zerodisk it first for security reasons, since i do this anyway to any drive..

Below i took sreenshots.... First ones are taken from completely blank hard drive, (after zerodisk the 4TB out from a PC), and the 2nd set of screenshots are "before* wiping out anything. (from the 2nd 4TB hard drive from NAS directly)
 

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illusionx

macrumors 6502
Jul 4, 2014
326
0
Brossard, QC
hard drive size

This is definitely the usb enclosure that does not support 4TB drives.

But OP seems to be saying he is using the same enclosure on the PC.