Re: [PATCH][BTRFS-PROGS][V1] btrfs filesystem df

[Goffredo Baroncelli <kreijack@gmail.com>]

On 10/09/2012 02:51 PM, Bart Noordervliet wrote:
> On Tue, Oct 9, 2012 at 1:38 PM, Goffredo Baroncelli<kreijack@gmail.com>  wrote:
>> Hi Bart,
>>
>> I replayed in another email to Hugo about that. Basically I am not contrary
>> to the change, only it is unrelated to my patches. In may patches I use the
>> function pretty_sizes() which adds the suffix KB, MB, and this function was
>> here from 2008....
>
> What we could do is change all callers to use pretty_sizes_r(), which
> most already do. We could then add a mode flag for SI units, say
> DF_HUMAN_SI_UNIT. I would then propose that we enable it by default,
> like the human-readable mode itself, and create an option to disable
> it.
>
> I like options a lot, but I like sensible defaults as well. We're
> hoping btrfs will be the next major filesystem for linux. If we
> succeed, it will have a long lifespan and be used on petabyte and
> maybe exabyte storage systems. If we keep showing binary bytes, the
> discrepancy between what the drive's box says and what 'df' says will
> become ever larger.

Pay attention to the fact that the hard-disk manufacturers use the SI 
units, but all the OS works in IEC (KiB, MiB...) units. E.g. btrfs 
allocates chunk in unit of 256MB; the chunks are divided in pages (4KiB).
I am not fully convinced that we should use SI everywhere; may be that 
let the user to select in which unit system the result should be printed 
may be the best compromise.

> This is probably the last chance we'll get to make
> btrfs set a good example by getting rid of this outdated method of
> display.
>
> I can make the changes to btrfs-progs if you like.

If you want, free feel to do anything. Please don't ask me the 
permission because I am not the "owner" of the code :-)

My patches and the one which we are discussing are completely unrelated, 
so these could be made/updated separately.
Pay attention only to the text alignment where needed.


>
> Best regards,
>
> Bart
>