Data recovery and disk repair questions and discussions related to old-fashioned SATA, SAS, SCSI, IDE, MFM hard drives - any type of storage device that has moving parts
Post a reply

HFS Formatted Seagate Drive

October 25th, 2019, 10:38

I have a 4TB Seagate drive, model ST4000DX002, that is showing up as a 1.8TB drive when I plug it into either a Windows, Mac, or Linux system.

Using TestDisk in Linux, I was able to locate the partition and create a raw image from it, but the image size is 1.8TB in size.

Any advice is appreciated.

Re: HFS Formatted Seagate Drive

October 25th, 2019, 12:49

Do you use older USB adaptor ? Which doesnt support 4k sector size?

Re: HFS Formatted Seagate Drive

October 25th, 2019, 14:36

That is possible. I didn't think of it. I will hook it directly into the system (live booting into Linux) and will post an update.

Re: HFS Formatted Seagate Drive

October 25th, 2019, 16:39

The problem appears to be a 32-bit LBA limitation. A capacity of 4TB requires 33 bits to report the total number of LBAs (512e mode). An adapter, or BIOS, or SATA driver that has a 32-bit limit will discard the uppermost bit.

    4TB - 2TiB = 1.8TB

Re: HFS Formatted Seagate Drive

October 28th, 2019, 9:26

@DR-Kiev and @fzabkar, that was definitely the problem - the USB to SATA adapter had a 32 bit limit. I have a 3.7 image file to work with now. Thank you for the advice, it's much appreciated.
Post a reply