Device's "stolen" sector

[Warner Losh]

On Tue, Jul 16, 2019 at 10:25 AM Domagoj Smolčić <rank1seeker at gmail.com>
wrote:

> 11.2-RELEASE-p9
>
> Tested with >1 disks:
> --
> SATA disk connected directly with SATA cable to MBO, shows correct amount
> of sectors.
>     diskinfo -v ada1
>
> When I connect it to the same MBO over USB to SATA adapter, 1 sector is
> missing (the last one)
>     diskinfo -v da0
>
> Having last sector inaccessible is a huge problem as many "things" use it
> for a metadata.
> This has many times caused MBR disks occasionally to not be visible at all
> while being 'da0' (gpart: No such geom: da0.)
> And also GPT disks to be in a [CORRUPT] state upon reattach directly to
> SATA interface.
>
> Before submitting a bug, there is only 1 variable left that I can't test,
> because I have only 1 USB to SATA adapter.
> It might be a hardware issue, so can someone else test this too?
>

On 11.x, I'd install the sg3_util port. You'll need the sg device in your
kernel. Use sg_readcap on /dev/da0 to see if the numbers match the devinfo
from ada1. If they match, then we have a bug in the da driver. If they
differ, you have hardware issues in the USB to SATA adapter.

Warner