Samsung HD154UI 1.5TB (1500GB) BIOS only sees 500GB (solved)

[ColinK]

I have a Samsung HD154UI 1.5TB SATA drive in a WinXP/Gigabyte K8VT800 system and have been using it as a second (data) drive for years. One morning after booting I could not access it. It showed in File Explorer but could not be opened, in Disk Management it just showed as a single unformatted 500GB partition with no empty space. Rebooting into BIOS settings the bios could only see it as a 500GB drive.
I could tell from holding the drive that the platters were spinning up and the heads were moving and there was no unusual noise so it didn't seem to be mechanical. I was sure there was no virus or malware on my pc which might have wiped the data so I figured all the data was still on the disc, somehow the disc was just telling the bios it was a 500GB drive.
First thing I did was to run TestDisk, it could only tell me it was a 500GB Disc with NTFS partition.
Next I started googling and found A-FF Repair Station, it confirmed the firmware was OK. So now I'm unsure why its registering as a 500GB drive.
Next I tried the OnTrack Easy Recovery Pro Trial. It could show me files and a directory structure (so FAT still good), a 1500GB partition on a 500GB drive and a sector by sector read showed that data was still on the disc (data not deleted); so at this point I'm ready to send it off to a lab for data recovery.
A little more googling showed up Atola HDD Capacity Restore. So I gave that a try and set the drive's capacity to the max 1500GB value and powered down. After a short wait I booted into BIOS and confirmed it was being seen as a 1500GB drive. Booting into Windows the system ran CHKDSK on the disc and it did some fixing (I forget what it said) and then in Windows I could see and use the drive quite normally as before. PHEW!!!

I'm posting this in case it can help someone else in future with the same issues as I spent 2 days doing this.

[Vulcan]

Congratulations on solving the problem

That Gigabyte BIOS issue is seen quite often here, e.g.:

hard-disk-capacity-t20165.html#p135318
wd10ears-1tb-failed-t19993.html#p134422
ntfs-became-32mb-raw-t18224.html
lost-partition-hitachi-1gb-hdt721010sla360-t15662.html#p103577
recovering-capacity-western-digital-wd20ears-2tb-t17374.html
(and others)

The BIOS had created an HPA, so you can use suitable utilities (e.g. MHDD or HDAT2 etc.) to detect that an HPA exists, and its size, which should be the approx 1TB of "lost capacity".

If I was in your situation now, I would be looking for a fix to the BIOS from Gigabyte, otherwise you might find yourself in the same situation again in the future, until the BIOS bug is fixed!

[ColinK]

This Gigabyte motherboard is around 5 years old now so I doubt there will be any firmware updates. I check on the @BIOS utility from time to time but its always the same Award bios version FG that I've had for years.

I've not heard of HPA, MHDD or HDAT2 before so I'll take a quick look at those and commit to memory, just in case. Thanks for the suggestions.

I've been thinking of building a new PC for a while now - this just might be the impetus.

[ColinK]

Interesting, I have never knowingly installed Express Recovery off the motherboard CD, and when booting if I press the Express Recovery key (F2 I think it was) I just get a message to insert the Express Recovery install CD.
In HxD I cannot see Award or BIOS at the end (last 32MB) of the drive either. I didn't want to let it search the entire drive as it was reporting a 7 hour search time.
Though I am convinced it was a Gigabyte problem and that HDD Capacity Restore was the solution.

[Vulcan]

Interesting, I have never knowingly installed Express Recovery off the motherboard CD

Neither have (at least some) other affected users - but the functionality to create an HPA is evidently still present in the BIOS (and is mistakenly triggered by the bug), since it does create an HPA! Normal applications don't (and typically can't) create an HPA.

HDD Capacity Restore was the solution.

Yes, that is one possible solution - others include MHDD, HDAT2 and recent versions of hdparm in Linux...

[ColinK]

Vulcan,
Thanks for all your explanations and useful reading. It sound like I was lucky to escape without any data loss.
This is a great forum.