pendrive clone impossible ?

Tomasz CEDRO tomek at
Sat Nov 30 22:28:21 UTC 2019

It looks like either GEOM is hiding something from application/me, or
pendrive itself is preventing MBR to be modified, or some sort of

I guess the first is more probable because DD'ing from /dev/md0,
/dev/zero, /dev/random devices always works, while DD'ing from da0.mbr
file never works. If pendrive was defending itself none of them would
be possible, right?

The Source pendrive was MBR. This is why I did /dev/zero -> /dev/da1
just to make sure there is no GPT of any sort on the Target pendrive,
nor MBR, also I could see where write was skipped.

This is the first time ever dd if=/dev/da0 of=/dev/da1 did NOT copy
the entire drive (the da1 attached GEOM noted inegrity checked MBR was
left blank the rest seems to be there). DD reported NO ERROR.. in fact
I got a standard summary on transferred bytes as operation was
completed successfully. I did not count all bytes transferred because
I never had to before. Is the OS hiding something from me? And from
DD? Is Penrdive messing with the GEOM / OS?

Because I need to finish quickly, I have used GPART to create and add
partitions by hand and I am DD'ing partition by partition. So far so

The Target pendrive is Kingston 128GB DTSE9 G2 USB3.0. Be careful with
that fellow!

Below is a Kingston's response cut-and-paste found on a forum where
another folk tried to install bootable system on a 32GB DTSE9 G2 ;-)

The first thing to point out is that a USB drive needs to be set as a
fixed drive which requires a tweak in the firmware, commonly refereed
to as "flipping the RMB". Not every firmware is suitable for such an
operation and since we use different flash controller providers to
meet the supply and demand for our products, we cannot check the
suitability of every firmware to be altered to accomodate booting from

Furthermore a standard USB drive is designed for sequential read and
writes, rather than random read and write speeds.

Booting from the USB will be very slow and will be a detriment to the
product, affectively its longevity.

Therefore we cannot guarantee the longevity and reliability of the
drive within the warranty period, and could offer no further support
in case of a drive failure.

This is the reason why we at Kingston do not support the bootability
of our commodity USB products.

If you purchased the DTSE9G2/32GB to be used specifically for this
purpose, we can only recommend that you return it to your supplier for
a refund and we apologise for any inconvenience this may cause.



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