New external harddrive and 106Mb unallocated - why

[Robert Moskowitz]

On 12/30/2013 06:46 PM, Chris Murphy wrote:
> On Dec 30, 2013, at 4:22 PM, Robert Moskowitz <rgm at htt-consult.com> wrote:
>
>> I just got a Toshiba Canvio Desk 2TB external HD that my plans are to delete the NTFS partition and put on an EXT4 one.
>>
>> Thing is the first 106MB are unallocated.  Why?
> Can you post the results from 'parted -l /dev/sdX u s p' that might be useful. This was new in box?

It is brand new from a sealed box.  And the the command seems to have 
done both drives:

# parted -l /dev/sdb u s p
Model: ATA TOSHIBA MK3261GS (scsi)
Disk /dev/sda: 320GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Disk Flags:

Number  Start   End    Size   Type     File system  Flags
  1      1049kB  525MB  524MB  primary  ext4         boot
  2      525MB   320GB  320GB  primary               lvm


Model: TOSHIBA External USB 3.0 (scsi)
Disk /dev/sdb: 2000GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Disk Flags:

Number  Start  End     Size    Type     File system  Flags
  1      106MB  2000GB  2000GB  primary  ntfs


Model: Linux device-mapper (linear) (dm)
Disk /dev/mapper/fedora_19-home: 280GB
Sector size (logical/physical): 512B/512B
Partition Table: loop
Disk Flags:

Number  Start  End    Size   File system  Flags
  1      0.00B  280GB  280GB  ext4


Model: Linux device-mapper (linear) (dm)
Disk /dev/mapper/fedora_19-root: 31.5GB
Sector size (logical/physical): 512B/512B
Partition Table: loop
Disk Flags:

Number  Start  End     Size    File system  Flags
  1      0.00B  31.5GB  31.5GB  ext4


Model: Linux device-mapper (linear) (dm)
Disk /dev/mapper/fedora_19-swap: 8389MB
Sector size (logical/physical): 512B/512B
Partition Table: loop
Disk Flags:

Number  Start  End     Size    File system     Flags
  1      0.00B  8389MB  8389MB  linux-swap(v1)



>
>> why the unallocated space; is this for sector replacement?
> Those are hidden on modern drives. When a physical sector is replaced, it no longer has an LBA, it's reassigned to the replacement. It's one of the reasons zeroing drives is an almost pointless security task because substituted sectors still contain data and are erase only the ATA Security Erase functions.

I thought so.  My revised thinking is that if I were to put this drive 
on a Win system and run the install software, this unused space will be 
used to create a partition for managing the backups.

>
>> Seems to be a rather nice unit.  Drive did not power up until I connected the USB; very convient not to have to unplug it to save on power usage.
> I see, it's in an enclosure, so chances are this is some weirdness on the part of the vendor who partitioned and pre-formatted the drive, rather than something the OEM did.

Toshiba in both cases.   Just probably different groups in Toshiba.

> I'm a nut, so I'd pull the drive, SATA or eSATA it to a board, and ATA Secure Erase the thing, take a baseline smartctl -x sample, put it back into its enclosure, and then GPT partition and format it.
>
> I might even go so far as to use gdisk to partition it twice, once outside and once inside the enclosure, and make sure the relevant data are identical, in particular the number of physical sectors. There are some enclosure firmware floating around that misreport the size of the drive so you end up with a drive partitioned one way in the enclosure and yet the backup partition is reported as missing or damaged when pulled from the enclosure. Such enclosure deserve to be returned as defective.

You are a nut, but does not mean some squirrel is not out to get you!  :)

This case is NOT made to be opened in the field.  So I am just going to 
use the Gnome disk gui tool, delete the partition, and go from there.

Unless the partd output I included at the beginning gives you any idea 
of something else going on...