[kwlug-disc] Don't do what I did...

[Chris Irwin]

On Mon, Mar 01, 2021 at 07:12:42PM -0500, CrankyOldBugger wrote:
> After much duckduckduckgo'ing, I finally figured out (to my
>embarrassment)  that my toaster is only 32 bit, thus a 2TB limit.
>
>I went on Amazon and picked up a newer (USB3 as well) toaster and sure
>enough, the larger drives were reading at their correct size.  Plus, with
>the older USB2 toaster, I was getting a max of 30MB/s transfer; the newer
>toaster gets me 80-90 MB/s.  So now the 4TB drives only take 3 days instead
>of a week or so...

I just encountered a similar issue today! I'm upgrading some drives to a 
larger size and used a Sabrent USB3 hot-swap device. It has been pretty 
handy in the past, and isn't even that old.

I guess it does some transparent LBA sector size remapping, to "help" if 
you want to use MBR on large format drives for some unknown reason. So 
if you plug in a drive with 4096-bit sectors , it "helpfully" translates 
that to 512-bit sectors.

I don't think I lost any usable space from this operation, but the real 
concern is that the parition table created in the USB caddy is *ENTIRELY 
UNREADABLE* when connected natively with SATA or another (sane) USB 
enclosure.

So you can connect a proper, functioning, *full* drive into this 
enclosure, and it looks totally empty, without even a partition table 
present.

That's annoying for a USB enclosure, and downright dangerous for your 
data in one designed to hotswap drives. I used this for backups!

Imagine connecting your backup drive to another computer to discover 
it's empty -- except it's not, just one of the enclosures lies about the 
physical layout of your drive.

Considering this device isn't even that old, I don't know how to figure 
out which devices are affected by this "helpfulness", and which ones 
work properly.

-- 
Chris Irwin

email:   chris at chrisirwin.ca
  xmpp:   chris at chrisirwin.ca
   web: https://chrisirwin.ca