Re: wrong values in "df" and "btrfs filesystem df"

["Helmut Hullen" <Hullen@t-online.de>]

Hallo, Calvin,

Du meintest am 09.04.11:

>> Nice picture. But it doesn't solve the problem that I need a
>> reliable information about the free/available space. And I prefer
>> asking with "df" for this information - "df" should work in the same
>> way for all filesystems.

> The problem is that the answer to the seemingly simple question: "How
> much more data can I put onto this filesystem?" gets pretty hard with
> btrfs.

> Your case is one of the simpler ones - To calculate the remaining
> space for files, you take the unused allocated data space (light blue
> on my picture), add the unallocated space (white), divide by the raid
> mode redundancy, and subtract some percentage (this is only an
> estimate, of course...) of that unallocated space for the additional
> metadata overhead.

That's simple?

Maybe I'm simple minded. But I expect the same meaning of the shown date  
with

        df <mointpoint>

regardless what kind of filesystem is mounted.
But no test item for an IQ test.

If the value of "available" is unresolvable then btrfs should not show  
any value.


Ok - there's a problem slightly similar to the "available" value of  
compressed partitions.

Viele Gruesse!
Helmut