Won't recognize 4TB HDD at full size even though I already have a 4TB HDD installed.

[Dougtron]

So I recently purchased a Seagate ST4000DM005 4TB HDD and Windows 7 Disk Management is only recognizing the drive as 1677.90 GB. However I have a Western Digital WDC WD40EZRZ 4TB HDD that I've had for almost two years and Disk Management recognizes it as 3725.90 GB. I tried downloading Seagates Disc Wizard tool and the disk management portion recognizes both of the HDD as only 1.69TB, even though the one HDD definitely using more space than that currently. I don't understand why it won't recognize one HDDs full capacity but has no problem with the other.

 

[tracerbullet]

Have you tried going to Computer Management, and then inside of it Disk Management? See if maybe it's recognized but just partitioned funny. If so try to extend it, maybe deleting whatever is in front of it if anything. If this sees it as the 1.69-ish as well that might lead you down a different path.

 

[VirtualLarry]

Could it be due to the Seagate DiskWizard being installed, and chopping the drive into discrete 2TB blocks for compatibility?

Also, could you be running an older SATA (AHCI) driver, for your SATA / AHCI controller, that might limit you to 2TB?

Also, has there ever been a USB external case or dock involved with this drive and/or system?

 

[Dougtron]

Disk Management shows it as one single 1.69~TB drive. It is partitioned using GPT (GUID).

The HDD is connected directly to my motherboard via SATA. I even tried using the port and cable that the correctly recognized 4TB HDD is using and still no dice. Device Manager says that I'm using the latest drivers for my SATA controllers.

 

[deustroop]

I note that Seagate's Disc Wizard sees the size of both the 4 TB drives @ 1.6TB. Windows 7 Disk Management however recognizes the WD as 3725.90 GB.I do not know the MB on the system but suggest setting the SATA controller to which the new disk is attached to IDE, see if that sorts this out.

 

[VirtualLarry]

Oh, you had that HDD in some system, or using some utility system software, or in a USB dock or caddy, that installed a "DCO" - Drive Configuration Overlay onto the drive, masking it's native capacity and capabilities.

That happened to me, with some 8TB WD Red drives, two of which I shucked from those EasyStore units, and then installed into a Lenovo NAS that was SATAII.

Well, the drives are capable of SATA6G, but that NAS was only SATAII. I discovered, when I got two more of those drives, and moved those two (used) drives into a 4-bay SATA6G QNAP TS-431 NAS, along with the two more (new) WD Red 8TB drives, that the "new" drives were identifying as SATA6G, but the older drives were identifying as SATAII. Which, I presume, is because the Lenovo NAS'es firmware, installed a DCO, which is semi-persistent.

You can remove the DCO by booting with Linux, and using some command-line hdparm commands. I didn't bother, as the gigE on the box is more of a bottleneck, but it's a cosmetic annoyance.

In your case, though, it's actually affecting capacity / functionality.

 

[Dougtron]

I used ATATool to get this information about the drive:

 

[VirtualLarry]

From those pics, it appears to be saying "DCO:NO", but I question a few things, is that a user-mode tool, or did you run it with Admin rights? Is it a DOS program, or a Win32 command-line ("console") application?

I would feel more confident in the readings, if you did it using a bootable Linux USB Live distro, like www.linuxmint.com .

 

[vailr]

Try: unplug all drives but the 4Tb drive, boot from a Windows 10 installation media (such as a bootable USB thumb drive), then completely delete all existing partitions. Go on (as if installing Win 10) to create 2x new 2Tb partitions. Power off the machine, then replace the Win 10 installation media with Win 7 installation media, and see if the installation process recognizes both 2Tb partitions. There may be certain HDD size limitations that Win 7 can't easily cope with, but Win 10 is okay with.
If you provide further information on the exact motherboard being used, then there may also be some drivers being required, when talking about Windows 7 installation.

 

[deustroop]

Is the WD Dynamic Drive Overlay installed on the WD drive ?

 

[Dougtron]

So I went into the BIOS and switched the SATA controller from AHCI to IDE and it recognized the full size of the drive. I then switched it back to AHCI and it still recognized the full drive so I thought I was all good.

I copied a bunch of stuff over to the new HDD but when I restarted my computer it still recognized the full size of the drive but said it was RAW data and needed to be formatted. I then went and switched it back to IDE mode and Windows spent a few hours doing CHKDSK and recovered some of the files.

Will I be fine if I leave my system in IDE mode? Should I keep trying to get it to work in AHCI mode?

 

[Ketchup]

IDE is fine.

 

[vailr]

when I restarted my computer it still recognized the full size of the drive but said it was RAW data and needed to be formatted.

AHCI mode has enough benefits to make it worthwhile getting working correctly. Go ahead and let Windows format the drive while in AHCI mode.

 

[lenjack]

ahci will perform lots better.