bug#10561: stat unclear about size on disk and type of blocks discussed

[Jim Meyering]

Pádraig Brady wrote:
...
>> As for %o, if you'd ask me what "I/O block size" means without any
>> context, I'm far from being sure I would answer it means size on
>> disk. I suggest to call this Size on disk, or Size used on the
>> filesystem.
>
> I/O implies transfer.
> So it corresponds to an "optimal transfer size hint"
> This value can be different at each layer, for example:
>
> $ stat -c "%o" .                # file level
> $ stat -f -c "%s" .             # file system level
> # blockdev --getioopt /dev/sda  # device level
>
>> I'm not sure what language should be used instead. Perhaps instead
>> of blocks the manual should talk about "data storage device blocks".
>
> I suppose we could clarify "I/O block size" a bit.
> How about s|I/O block size|optimal I/O block transfer size|

or even without "block",

  "optimal I/O transfer size"

Either way.  Thanks.