Tried to use my 3TB drive in a USB enclosure, now reports only 746GB even internally [duplicate]
I have two 3TB Hitachi 5k3000 Desktar drives that I want to use as data drives, not boot drives. When I was originally trying to install them I wanted to mirror them using my hardware raid but I couldn't get them recognized, my motherboard is pretty old (P5N32-SLI) but the BIOS and RAID firmware are as up to date as possible.
Whilst trying to get the drives recognized I found you need to initialize them to GPT to see past the 2.2TB barrier, I tried initializing one in Windows (7 x64) via a USB drive enclosure and even though it was set to GPT it never reported the correct size only 746GB.
Next, I tried initializing the other disk connected via the internal SATA ports on my motherboard and it actually reported the correct size (in MBR mode it reported 2.2TB and 746GB, when I switched to GPT it showed one continuous volume.) However, now I can't get my other one to reinitialize, I tried switching it back to MBR but that did not make a difference. I suspect Windows is caching something about this drive that I'm not seeing, but would greatly appreciate some guidance.
Edit: I don't want to use these with my USB enclosure, I want them internal. One drive does work as expected internally, just the one I originally tried to initialize via the enclosure won't re-initialize internally with the correct space.
Solution 1:
Typical USB drive enclosures have historically only supported up to 1.5 TB of capacity. I have a feeling this has something to do with the 32bit nature of the enclosure, but I could be totally off on that one. Make sure the enclosure's specifications state that it supports drives larger than 1.5 or 2 TB.
Thus far, I have only seen USB 3 (SuperSpeed) enclosures supporting anything at or larger than 3 TB.
Edit (from comments): If you're concerned that Windows might be caching something about the drive then you can try to fix it on another machine, or access it using a live cd like GParted.
Solution 2:
Try zeroing out the first 1k (Boot sector) of the drive, Use Hitachi's "Drive Fitness Test" boot disc to do this.
http://www.hitachigst.com/support/downloads/