On Fri, Nov 09, 2007 at 02:00:14AM -0500, Daniel Ouellet wrote:
> Hi,
>
> I am trying to find a way ti identifying sparse files properly and
> quickly and find a way to rectify the situation.
>
> Any trick to do this?
>
> The problem is that overtime looks like I am ending up with lots of them
> and because I have to sync multiples servers together the sparse files
> makes the sync painful over time as well as huge obviously and slow. I
> am talking multiple GB's here.
>
> So far the only way I have do it is with rsync and -S options, but then
> the sync process takes a lots of time and when you need to sync multiple
> boxes multiple times per hours, it end up not be able to do it anymore
> and the process is not finish and it is suppose to start again.
>
> The other way that I found is to use dump and then restore, but that
> also is painful to do on live systems obviously. I need to find a way to
> clean the source, so that the sync system do their stuff easy. If I
> simply sync with the sparse file, sure I can do that, but then, the
> problem is the destinations runs out of space as the sparse gets to big
> over time.
>
> Google also pointed out that may be "FIBMAP ioctl" may have done to job,
> may be, but that was kill by Theo on 2007/06/02 09:14:36. I assume for
> many good reason for sure, so I didn't pursue that anymore.
>
> Then may be filefrag -v might work, but not much success there either.
>
> So, I am running out of ideas and may be there isn't any way to do this,
> I however hope there is.
>
> If it is not possible to correct the problem in a cronjob fashion or
> something, may be how could I possible find sparse files efficiently?
>
> At a minimum, if I could find the file getting out of control, then I
> could at a minimum delete them and copy them from the source again and
> reduce the problem of the sparse files.
I do not get you at all. "Unsparsing" the file will only make it use
more disk space.
Actually, since some time cp(1) will actively create sparse files if it can.
>
> Any clue as to how to tackle this problem, or any trick around it?
I really do not understand the problem here. But you might be able to
detect sparse files compartaring the size vs the number of blocks it uses.
-Otto
