# [SOLVED] 4TB USB disk partially recognized

## VinzC

Hi all.

I recently bought a Seagate 4TB USB disk with a USB3 connector. I could plug it on my Gentoo box but I had a few troubles since day one, most of which is about the system not seeing more than the first partition. I could partition it with gdisk only and I could only format the disk with gparted. I could also backup my Gentoo machine on that disk that day.

Later on I plugged the disk on my laptop using the USB3 connector and it worked like a charm, both partitions, clear and encrypted were detected and could be mounted. Still, on my Gentoo box, no way to use the disk off the USB2 connectors. And I unfortunately have no USB2 circuitry on my motherboard.

The disk is a 2.5 inches SATA drive that I initially intended to mount into my Gentoo machine's case. But I made up my mind and decided to carry it as a portable backup device instead of having it powered and mounted each time the machine starts, leaving it to the mercy of thunder strikes (yes, I'm being paranoid).

Here's the detection log from the kernel.

```
[26533.274660] usb 1-1.6: new high-speed USB device number 4 using ehci-pci

[26533.420236] usb 1-1.6: New USB device found, idVendor=0bc2, idProduct=ab28

[26533.420242] usb 1-1.6: New USB device strings: Mfr=2, Product=3, SerialNumber=1

[26533.420245] usb 1-1.6: Product: BUP BK

[26533.420247] usb 1-1.6: Manufacturer: Seagate

[26533.420250] usb 1-1.6: SerialNumber: NA7P2LTA

[26533.420567] usb-storage 1-1.6:1.0: USB Mass Storage device detected

[26533.420629] scsi host6: usb-storage 1-1.6:1.0

[26534.423538] scsi 6:0:0:0: Direct-Access     Seagate  BUP BK           0304 PQ: 0 ANSI: 6

[26534.423701] sd 6:0:0:0: Attached scsi generic sg3 type 0

[26534.427994] sd 6:0:0:0: [sdc] Spinning up disk...

[26535.429686] .....ready

[26539.450048] sd 6:0:0:0: [sdc] Very big device. Trying to use READ CAPACITY(16).

[26539.450424] sd 6:0:0:0: [sdc] 7814037167 512-byte logical blocks: (4.00 TB/3.63 TiB)

[26539.450428] sd 6:0:0:0: [sdc] 2048-byte physical blocks

[26539.560702] sd 6:0:0:0: [sdc] Write Protect is off

[26539.560709] sd 6:0:0:0: [sdc] Mode Sense: 4f 00 00 00

[26539.561770] sd 6:0:0:0: [sdc] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA

[26539.562521] sd 6:0:0:0: [sdc] Very big device. Trying to use READ CAPACITY(16).

[26539.596816]  sdc: sdc1

[26539.597833] sd 6:0:0:0: [sdc] Very big device. Trying to use READ CAPACITY(16).

[26539.600701] sd 6:0:0:0: [sdc] Attached SCSI disk

[26659.609305] sd 6:0:0:0: [sdc] Very big device. Trying to use READ CAPACITY(16).

[26659.612815]  sdc: sdc1

[27751.340789] sd 6:0:0:0: [sdc] Very big device. Trying to use READ CAPACITY(16).

[27751.347070]  sdc: sdc1
```

Here's what gdisk has to say about it

```
GPT fdisk (gdisk) version 0.8.10

Partition table scan:

  MBR: protective

  BSD: not present

  APM: not present

  GPT: present

Found valid GPT with protective MBR; using GPT.

Disk /dev/sdc: 7814037167 sectors, 3.6 TiB

Logical sector size: 512 bytes

Disk identifier (GUID): 381ECDBA-4994-41C1-BCAE-A24E4DA94149

Partition table holds up to 128 entries

First usable sector is 34, last usable sector is 7814037133

Partitions will be aligned on 2048-sector boundaries

Total free space is 2014 sectors (1007.0 KiB)

Number  Start (sector)    End (sector)  Size       Code  Name

   1            2048      6442452991   3.0 TiB     8300  Backup

   2      6442452992      7814037133   654.0 GiB   8300  e-Backup
```

... and the listing from /dev.

```
brw-rw---- 1 root disk 8, 32 17 jan 17:39 /dev/sdc

brw-rw---- 1 root disk 8, 33 17 jan 17:39 /dev/sdc1
```

Here's what happens when I attempt to mount the first partition

```
mount: /dev/sdc1 is write-protected, mounting read-only

mount: wrong fs type, bad option, bad superblock on /dev/sdc1,

       missing codepage or helper program, or other error

       In some cases useful info is found in syslog - try

       dmesg | tail or so.
```

In case you ask, I have another USB3 disk, 1TB that I casually use, not a problem with it, even through USB2 connectors:

```
[29880.785955] usb 2-1.5: new high-speed USB device number 5 using ehci-pci

[29880.958846] usb 2-1.5: New USB device found, idVendor=059f, idProduct=104a

[29880.958850] usb 2-1.5: New USB device strings: Mfr=2, Product=3, SerialNumber=1

[29880.958852] usb 2-1.5: Product: Minimus USB 3

[29880.958853] usb 2-1.5: Manufacturer: LaCie

[29880.958854] usb 2-1.5: SerialNumber: 00000000e4517576105a

[29880.959112] usb-storage 2-1.5:1.0: USB Mass Storage device detected

[29880.959359] scsi host8: usb-storage 2-1.5:1.0

[29889.688170] scsi 8:0:0:0: Direct-Access     ST2000DL 001-9VT156       CC41 PQ: 0 ANSI: 0

[29889.688330] sd 8:0:0:0: Attached scsi generic sg3 type 0

[29889.688957] sd 8:0:0:0: [sdc] 3907029168 512-byte logical blocks: (2.00 TB/1.81 TiB)

[29889.689966] sd 8:0:0:0: [sdc] Write Protect is off

[29889.689971] sd 8:0:0:0: [sdc] Mode Sense: 23 00 00 00

[29889.690957] sd 8:0:0:0: [sdc] No Caching mode page found

[29889.690960] sd 8:0:0:0: [sdc] Assuming drive cache: write through

[29889.742666]  sdc: sdc1 sdc2

[29889.746129] sd 8:0:0:0: [sdc] Attached SCSI disk

[29952.595121] EXT4-fs (sdc1): warning: maximal mount count reached, running e2fsck is recommended

[29952.611592] EXT4-fs (sdc1): mounted filesystem with ordered data mode. Opts: (null)
```

Here's what happens on my laptop when I plug the the 4TB disk in its USB3 connector (like 3 minutes later)

```
[174356.319372] usb 4-1: new SuperSpeed USB device number 4 using xhci_hcd

[174356.336332] usb 4-1: New USB device found, idVendor=0bc2, idProduct=ab28

[174356.336339] usb 4-1: New USB device strings: Mfr=2, Product=3, SerialNumber=1

[174356.336343] usb 4-1: Product: BUP BK

[174356.336346] usb 4-1: Manufacturer: Seagate

[174356.336349] usb 4-1: SerialNumber: NA7P2LTA

[174356.337196] usb-storage 4-1:1.0: USB Mass Storage device detected

[174356.338161] scsi8 : usb-storage 4-1:1.0

[174357.335973] scsi 8:0:0:0: Direct-Access     Seagate  BUP BK           0304 PQ: 0 ANSI: 6

[174357.336453] sd 8:0:0:0: Attached scsi generic sg2 type 0

[174357.339303] sd 8:0:0:0: [sdb] Spinning up disk...

[174358.342598] .....ready

[174362.358269] sd 8:0:0:0: [sdb] Very big device. Trying to use READ CAPACITY(16).

[174362.358473] sd 8:0:0:0: [sdb] 7814037167 512-byte logical blocks: (4.00 TB/3.63 TiB)

[174362.358478] sd 8:0:0:0: [sdb] 2048-byte physical blocks

[174362.483593] sd 8:0:0:0: [sdb] Write Protect is off

[174362.483608] sd 8:0:0:0: [sdb] Mode Sense: 4f 00 00 00

[174362.483979] sd 8:0:0:0: [sdb] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA

[174362.484477] sd 8:0:0:0: [sdb] Very big device. Trying to use READ CAPACITY(16).

[174362.557980]  sdb: sdb1 sdb2

[174362.558663] sd 8:0:0:0: [sdb] Very big device. Trying to use READ CAPACITY(16).

[174362.559310] sd 8:0:0:0: [sdb] Attached SCSI disk

[174368.009197] EXT4-fs (sdb1): mounted filesystem with ordered data mode. Opts: (null)
```

... and what happens when I plug it into a USB2 port on my laptop

```
[174881.038946] usb 4-2: new SuperSpeed USB device number 5 using xhci_hcd

[174881.055894] usb 4-2: New USB device found, idVendor=0bc2, idProduct=ab28

[174881.055901] usb 4-2: New USB device strings: Mfr=2, Product=3, SerialNumber=1

[174881.055905] usb 4-2: Product: BUP BK

[174881.055908] usb 4-2: Manufacturer: Seagate

[174881.055911] usb 4-2: SerialNumber: NA7P2LTA

[174881.056943] usb-storage 4-2:1.0: USB Mass Storage device detected

[174881.057257] scsi9 : usb-storage 4-2:1.0

[174882.055606] scsi 9:0:0:0: Direct-Access     Seagate  BUP BK           0304 PQ: 0 ANSI: 6

[174882.056644] sd 9:0:0:0: Attached scsi generic sg2 type 0

[174882.063501] sd 9:0:0:0: [sdb] Spinning up disk...

[174883.066186] ......ready

[174888.085640] sd 9:0:0:0: [sdb] Very big device. Trying to use READ CAPACITY(16).

[174888.085878] sd 9:0:0:0: [sdb] 7814037167 512-byte logical blocks: (4.00 TB/3.63 TiB)

[174888.085888] sd 9:0:0:0: [sdb] 2048-byte physical blocks

[174888.824557] sd 9:0:0:0: [sdb] Write Protect is off

[174888.824566] sd 9:0:0:0: [sdb] Mode Sense: 4f 00 00 00

[174888.825023] sd 9:0:0:0: [sdb] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA

[174888.825463] sd 9:0:0:0: [sdb] Very big device. Trying to use READ CAPACITY(16).

[174888.898449]  sdb: sdb1 sdb2

[174888.899659] sd 9:0:0:0: [sdb] Very big device. Trying to use READ CAPACITY(16).

[174888.900464] sd 9:0:0:0: [sdb] Attached SCSI disk

[174979.722379] EXT4-fs (sdb1): mounted filesystem with ordered data mode. Opts: (null)
```

I still can «mount» and use both partitions from my laptop.

Linux mint Kernel 3.11-0-12-generic on my laptop. Gentoo Kernel 4.0.9 on my Gentoo box.

Do you see something wrong in there? What are my options?

----------

## Buffoon

Get an add-on USB3 card?

----------

## VinzC

 *Buffoon wrote:*   

> Get an add-on USB3 card?

 

I'd like to investigate that way only when I'm running out of software solution for sure...

----------

## schorsch_76

Hm, 

did you upgrade the kernel lately? 

Is the GPT option enabled?

Could you try an older kernel still on the boot partition?

Try to reemerge sys-fs/e2fsprogs.

As i think of the USB2 problem, my guess is that the Power on the USB port is not enough. Try to use an external USB3 Hub to power it up.

----------

## VinzC

 *schorsch_76 wrote:*   

> Hm, 
> 
> did you upgrade the kernel lately? 

 

Well, a few weeks ago, yes, I did.

 *schorsch_76 wrote:*   

> Is the GPT option enabled?

 

I found no such option in the kernel. BTW Isn't GPT boot-specific? If yes, my USB disk is not used for booting, just backing up data casually when plugged in.

 *schorsch_76 wrote:*   

> Could you try an older kernel still on the boot partition?

 

Wish I could  :Sad:  . The oldest kernel in /boot is 4.0.5. I might try an older 3.x series.

 *schorsch_76 wrote:*   

> Try to reemerge sys-fs/e2fsprogs.

 

Hmmm... My guess is that it's a hardware/kernel/firmware issue as only one out of the two partitions are listed. Moreover I *could* format the disk on the command line, too, as soon as gparted finished prep'ing it. What is your idea behind?

 *schorsch_76 wrote:*   

> Try to use an external USB3 Hub to power it up.

 

I have none in stock  :Sad:  . I'll try and find one and report.

Anyway, I assumed this might be a BIOS issue and upgraded my EFI BIOS, which I only rarely do. So I picked up one that reportedly improved compatibility with USB drives. Version 3706 was the one so I picked 3802.

Verdict: pointless, didn't fix the issue.

----------

## NeddySeagoon

VinzC,

It looks like your are missing GPT support in your kernel.

The Protective MSDOS partition table is being seen and used, hence only one partition. 

You need 

```
 [*]   EFI GUID Partition support 
```

```
  │ CONFIG_EFI_PARTITION:                                                   │  

  │                                                                         │  

  │ Say Y here if you would like to use hard disks under Linux which        │  

  │ were partitioned using EFI GPT.
```

----------

## VinzC

 *NeddySeagoon wrote:*   

> VinzC,
> 
> It looks like your are missing GPT support in your kernel.

 

Oh my gosh, I feel like a n00b... But a happy one! Woohoo! That did it, definitely, thanks a lot NeddySeagoon.

----------

