XFS realtime O_DIRECT failures

[Alan Cook]

On Wed, Nov 9, 2011 at 2:01 AM, Christoph Hellwig <hch at infradead.org> wrote:
> It might sounda a bit harsh, but the problem is that use the realtime
> subvolume.  It hasn't really been maintained or been part of the tested
> setup, and most distros in the know ship with it disabled.  I went
> through and fixed it when we got bug reports once in a while, and I'm
> happy to look into your issues once I get a bit spare time, but in
> general use is highly discouraged.   Is there any specific reason why
> you want to use the RT subvolume?

I am streaming high-resolution images to be compressed through
hardware and need to separate the data from the meta data for
compression purposes.  XFS gave that for free if I used a realtime
subvolume.

I originally started on kernel 2.6.27 (CentOS 5.5) which had no issues
with the RT subvolume and direct writes.  I was then moved to kernel
2.6.32 (SUSE 11) which does have the issue.

I appreciate your willingness to help.  Are there any alternatives or
suggestions for splitting the data and meta data?  Any direction you
can give on where to start looking or what I could do to track down
the exact cause of the bug?

Thanks.