[GTALUG] 10TB drive seen as a 2TB drive (twice?)

[D. Hugh Redelmeier]

| From: Evan Leibovitch via talk <talk at gtalug.org>

| It's not an Xmas present as it was bought a few weeks ago, but I'm trying
| to install a 10TB WD (Red Pro) disk and it's not exactly going to plan.

Red Pro seem to be "top of the line".  I think that it doesn't use
SMR (good), but I don't know.

You don't say what your USB <-> SATA device is.  I think that matters.
But even if you did, they are often poorly documented with respect to
things that the manufacturers think might confuse users.  You appear
to be in that territory.

Your USB device is surely the reason that your computer sees 512 byte
sectors, even though your drive prefers/demands 4 KiB sectors.
Superstitiously, I wonder whether that alone might disturb the
geometry such that transferring the disk from the external to internal
would not work.

If your USS <-> SATA device is old, it might not even support sizes
over 2T.

(I have a couple of older NAS boxes that claim they only support SATA
drives up to 2T.)

Suggestions: one of

- Mount your drive in its ultimate destination (internal bay, with
  SATA connection) and set it up there.

- Mount your drive in a different computer (with a similar OS release)
  and set it up there.  The reason for the "similar OS release"
  suggestion is that filesystem details details might (but it isn't
  common).

- Buy a new (and well-documented) external USB<->SATA device

================

Western Digital called 4 KiB sectors "Advanced Formatting".  The
transition from 512 B sectors came about a decade ago, painfully.

During the transition, all sorts of hacks were used to paper over the
problem.  Some devices with 4 KiB partitions would pretend and fake
having 512 B partitions if they thought that the computer didn't
understand 4 KiB.  I remember all this faking causing its own set of
problems.

I seem to remember USB<->SATA devices presenting 512 B sectors on the
USB side, even if the drive uses 4 KiB sectors.  This might cause
problems (I don't know).

(Off topic: A single "real" blocksize for SSDs doesn't exist.  There
are several kinds of block sizes for a particular device.  All this is
hidden from the computer.  Too bad: the OS cannot optimize I/O
appropriately.)

The main point of Advanced Formatting was to increase density: each
sector has overhead on the disk platter and so reducing the number of
sectors reduced the overhead.

A second reason was that sector addressing of some kind was limited to
2T / 512 or 16T / 4096, so Advanced Formatting allowed a larger
capacity.  At least for MBR partitioning.  But we mostly use GPT
partitioning now, eliminating that problem (I think).

Does your computer use "legacy" booting or EFI?