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repair 8TB sata drive that reports wrong size - HOWTO?

ipanini

ipanini

macrumors newbie
Original poster
Jun 22, 2024
3
0
Hi,

I'm looking for help to try to fix a harddrive that is reporting a completely wrong size.
It is a Seagate Archive 8TB harddrive. Research has 16383 cylinders, 16 heads and sector(size?) is 63.

I would expect that in terminal working with diskutil or fdisk should be able to reformat the disk back to it's 8TB.
The disk has been laying around for years, I don't know what was on it previously.

diskutil list shows the drive as follows:

/dev/disk6 (internal, virtual):


#: TYPE NAME SIZE IDENTIFIER
0: FDisk_partition_scheme +4.1 GB disk6
1: Apple_Boot 67.1 MB disk6s1
2: Apple_HFS 4.1 GB disk6s2

Any help or pointer will be hugely appreciated!
Thanks for helping out!
 
1.
I'm assuming you have all important data from that drive backed up.
Have you tried erasing the disk with Apple's "Disk Utility"?
(Use "GUID" and "MacOS Extended (Journaled)" from the DropDown Menus.)

2.
The terminal output is incomplete, because it only shows one virtual volume.
The complete output of diskutil list would be helpful.
 
Last edited:
Just some thoughts...

Does it have any "proprietary" Seagate software on it?
Sometimes these things would come with a "protected partition" that you could only remove by using the mfr. software.

Do you have a PC available?
If so, have you tried connecting it to that, to see what kind of report you get?

Again, if you have a PC available...
Have you tried re-formatting it on the PC first, and THEN taking it back to the Mac and trying again?
 
It's a commonly reported problem (search for "Seagate HDD reports 4.1GB size" or similar. It appears to be some result reported from Seagate hard drive firmware.
The false drive identity likely is because some failing (or failed) blocks trigger an incorrect drive capacity. The 4.1GB size (usually specifically that size) will show up quite often in internet searches for this problem, and the reports are almost always about Seagate drives
What's the fix? Replace the drive.
 
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Reactions: Fishrrman and tonmischa
tonmischa said:
1.
I'm assuming you have all important data from that drive backed up.
Have you tried erasing the disk with Apple's "Disk Utility"?
(Use "GUID" and "MacOS Extended (Journaled)" from the DropDown Menus.)

2.
The terminal output is incomplete, because it only shows one virtual volume.
The complete output of diskutil list would be helpful.
Click to expand...
Here you are:

Code: 
macpro2:~ erwin$ sudo diskutil list
Password:
/dev/disk0 (internal, physical):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *500.1 GB   disk0
   1:                        EFI EFI                     209.7 MB   disk0s1
   2:                 Apple_APFS Container disk1         499.9 GB   disk0s2

/dev/disk1 (synthesized):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      APFS Container Scheme -                      +499.9 GB   disk1
                                 Physical Store disk0s2
   1:                APFS Volume SSD                     191.1 GB   disk1s1
   2:                APFS Volume Preboot                 25.7 MB    disk1s2
   3:                APFS Volume Recovery                507.6 MB   disk1s3
   4:                APFS Volume VM                      20.5 KB    disk1s4

/dev/disk2 (internal, physical):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *1.0 TB     disk2
   1:                        EFI EFI                     209.7 MB   disk2s1
   2:                 Apple_APFS Container disk4         500.2 GB   disk2s2
   3:                 Apple_APFS Container disk5         499.8 GB   disk2s3

/dev/disk3 (internal, physical):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *4.3 GB     disk3
   1:                        EFI EFI                     209.7 MB   disk3s1
   2:                 Apple_APFS                         4.1 GB     disk3s2

/dev/disk4 (synthesized):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      APFS Container Scheme -                      +500.2 GB   disk4
                                 Physical Store disk2s2
   1:                APFS Volume MacOS - Gegevens        80.7 GB    disk4s1
   2:                APFS Volume Preboot                 83.6 MB    disk4s2
   3:                APFS Volume Recovery                528.9 MB   disk4s3
   4:                APFS Volume VM                      12.9 GB    disk4s4
   5:                APFS Volume MacOS                   11.3 GB    disk4s5

/dev/disk5 (synthesized):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      APFS Container Scheme -                      +499.8 GB   disk5
                                 Physical Store disk2s3
   1:                APFS Volume data                    2.8 MB     disk5s1

/dev/disk6 (internal, virtual):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:     FDisk_partition_scheme                        +4.1 GB     disk6
   1:                 Apple_Boot                         67.1 MB    disk6s1
   2:                  Apple_HFS                         4.1 GB     disk6s2

macpro2:~ erwin$
 
ipanini said:
Here you are:
Click to expand...
Thank you.

Let's focus on disk3 and disk6.

disk3 is - very likely - the physical Seagate Archive Drive. (It says "internal", so you have it probably built into a MacPro?)
It is formatted as 4 GB drive (Problem 1) with a APPLE_APFS partition (Problem 2*) which is not linked to any synthesized APFS Container (Problem 3**)

(Notes:
* - SSDs should be formatted as APFS, rotating hard drives as HFS (aka MacOS Extended)
** - look at disk2s2 and disk2s3: they are both valid APPLE_APFS Containers that are clearly linked to synthesized volumes disk4 and disk5
)

disk6 is some kind of orphaned virtual partition, that may or may not be linked to the physical disks3. (It's impossible to tell without further info.)

In my opinion, you have one option left:

- Open Applications --> Utilites --> Disk Utility.
- Click View in the Toolbar.
- Select "Show all Devices".
- See the sidebar for all your hard disks. You should see your SEAGATE Archive drive (probably with some long number like ST8000AS0002 or similar). Feel free to post a screenshot if you are unsure.
- Selcet that "SEAGATE ST8000AS0002" entry and select "Erase" from the Toolbar. (This will DELETE ALL DATA on that drive. Be warned.)
- Choose Format "MacOS Extended (Journaled)" and "GUID Partition Map".
- After the format is finished, look at the size of the newly created drive.
If it is still ~4GB, your drive's firmware is indeed dead beyond repair.
If it is 8TB now, you have to decide for yourself, if you want to trust that 9-year-old hard disk with your data.

Good luck!
 
Last edited:
tonmischa said:
Thank you.

Let's focus on disk3 and disk6.

disk3 is - very likely - the physical Seagate Archive Drive. (It says "internal", so you have it probably built into a MacPro?)
It is formatted as 4 GB drive (Problem 1) with a APPLE_APFS partition (Problem 2*) which is not linked to any synthesized APFS Container (Problem 3**)

(Notes:
* - SSDs should be formatted as APFS, rotating hard drives as HFS (aka MacOS Extended)
** - look at disk2s2 and disk2s3: they are both valid APPLE_APFS Containers that are clearly linked to synthesized volumes disk4 and disk5
)

disk6 is some kind of orphaned virtual partition, that may or may not be linked to the physical disks3. (It's impossible to tell without further info.)

In my opinion, you have one option left:

- Open Applications --> Utilites --> Disk Utility.
- Click View in the Toolbar.
- Select "Show all Devices".
- See the sidebar for all your hard disks. You should see your SEAGATE Archive drive (probably with some long number like ST8000AS0002 or similar). Feel free to post a screenshot if you are unsure.
- Selcet that "SEAGATE ST8000AS0002" entry and select "Erase" from the Toolbar. (This will DELETE ALL DATA on that drive. Be warned.)
- Choose Format "MacOS Extended (Journaled)" and "GUID Partition Map".
- After the format is finished, look at the size of the newly created drive.
If it is still ~4GB, your drive's firmware is indeed dead beyond repair.
If it is 8TB now, you have to decide for yourself, if you want to trust that 9-year-old hard disk with your data.

Good luck!
Click to expand...
Ok, thanks for your elaborate reply!
I've done exactly as you suggested, but the drive stays at exactly 4.33 GB, so I'll have to accept that it is dead.

One more question though:
A couple of years ago (I think approx 2021) I visited an Apple Service guy in the Netherlands. He put a new SSD drive in my wife's iMac, but that is not the point. I also had a Samsung 850 EVO 4 TB 2.5" ssd laying around that reported the wrong size, so a bit similar to the 8 TB Seagate.
I remember that he used a particular version of macOS because that contained a version of Disk Utility that could do more or do things differently, unfortunately I do not know what macOS version that was.
Would you maybe know about Disk Utility differences among macOS versions?
 
Sorry about your disk.

ipanini said:
Would you maybe know about Disk Utility differences among macOS versions?
Click to expand...
Apple changed the Disk Utility interface between 10.12 and 10.13 (Sierra and High Sierra).
A major drawback was that you could no longer perform operations on multiple discs at once. (For example: select all your partitions and press "First Aid".) Now you have to check/repair each disk one by one.
However, apart from the addition of APFS, the functionality of the application is basically the same.

This is the only major change (or difference) that I am currently aware of. Perhaps others can chime in?
 
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