Does your application depend on, or report, free disk space? Re: F20 Self Contained Change: OS Installer Support for LVM Thin Provisioning

[Chris Murphy]

On Jul 26, 2013, at 3:34 PM, David Lehman <dlehman at redhat.com> wrote:

> On Fri, 2013-07-26 at 22:59 +0200, Miloslav Trmač wrote:
>> On Fri, Jul 26, 2013 at 10:17 PM, DJ Delorie <dj at redhat.com> wrote:
>>> 
>>>> If your package reports disk space usage to users, and bases this on
>>>> filesystem free space, please consider whether it might need to take
>>>> LVM thin provisioning into account.
>>> 
>>> Perhaps you could include a small code snippet explaining *how* to do
>>> this?  Is there an lvm_thin_statfs() we can use?
>> 
>> I'd love to, but I don't know how.  David, could you suggest something, please?
> 
> As noted by drago01, this is not exactly new or specific to thinp -- a
> similar situation exists with btrfs. 

The RAID 1/10 problem where df reports free space as the size of the volume, not the actual amount of stuff that can be stored on the volume? Or is there another case?

It does seem to be a problem that df works this way with btrfs. It's one thing for 'btrfs df' to do it's own thing, but for df to do this doesn't seem like a good idea.


Chris Murphy