Caveat emptor 128GB USB sticks

Further to my recent post regarding 128GB USB sicks (and the VERY embarrassing 'SOLVED' due to my forgetting to create filesystems after using fdisk - call me a geriatric if you will) I've news rather more interesting to report.

To recap briefly, I purchased five cheap ($7) Chinese 128GB USB sticks for use initially as temporary secondary backup devices to evaluate them. My first requirement was to backup a commercial 128GB USB stick in order to safeguard my $70 investment. I assumed that the manufacturer may have used some sort of anti-copy protection similar to that on DVDs, so wasn't surprised when the first attempt failed. The second attempt used a second of the new sticks with similar results.

I then moved to the second requirement, to reformat a stick with two 16GB ext4 partitions and a single 96GB ext4 partition for the remainder. This appeared to be successful since the two 16GB partitions mounted successfully, but the third gave a "bad partition" error. This got me suspicious, so I fdisk'd the remaining two new sticks, only to find, not the single NTFS partition I'd expected, but:

Code:qtm:~># fdisk /dev/sdd1
Welcome to fdisk (util-linux 2.33.1).

Disk /dev/sdd1: 125 GiB, 134217711616 bytes, 262143968 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x00000000

Device Boot Start End Sectors Size Id Type
/dev/sdd1p1 4294967295 8589934589 4294967295 2T ff BBT
/dev/sdd1p2 4294967295 8589934589 4294967295 2T ff BBT
/dev/sdd1p3 4294967295 8589934589 4294967295 2T ff BBT
/dev/sdd1p4 4294967295 5035196669 740229375 353G ff BBT

qtm:~>#The three BBT partitions sized at 2TB - ??? - plus a fourth smaller BBT suggest that the device is in fact a "composite storage unit" of some sort. My deduction is that some - perhaps all - "128GB" USB sticks consist PHYSICALLY of 4 x 32GB memory cells "tied together" by a "management unit" that makes them appear as a single 128GB device. REFORMAT THIS AT YOUR PERIL!!!

Further experimenting with the initial two sticks confirmed something very strange going on. I first attempted a standard repartition into a single XFAT partition, but this failed on both. I then used the standard "trick" of wiping the first few megabytes of the device:

Code:qtm:~># dd if=/dev/zero of=/dev/sdd bs=4M count=1000
dd: error writing '/dev/sdd': No space left on device
474+0 records in
473+0 records out
1985966080 bytes (2.0 GB, 1.8 GiB) copied, 2.4177 s, 821 MB/s
qtm:~>#... so dd could only find 2GB of storage on the device. Attempting to write a partition table then gave:

Code:qtm:~># fdisk /dev/sdd
Welcome to fdisk (util-linux 2.33.1).

Device does not contain a recognized partition table.
Created a new DOS disklabel with disk identifier 0xb375fedc.

Command (m for help): o
Created a new DOS disklabel with disk identifier 0xa7c1ff84.

Command (m for help): n
Partition type
p primary (0 primary, 0 extended, 4 free)
e extended (container for logical partitions)
Select (default p):

Using default response p.
Partition number (1-4, default 1):
First sector (2048-3878839, default 2048):
Last sector, +/-sectors or +/-size{K,M,G,T,P} (2048-3878839, default 3878839):

Created a new partition 1 of type 'Linux' and of size 1.9 GiB.

Command (m for help): q

qtm:~>#In other words, the "128GB USB stick" is now a 2GB device, and I've no idea how to change this.

All suggestions appreciated.