Fragmentation on XFS

Jamie Lokier
Mon, 25 Feb 2008 17:20:46 -0000

Rob Bosch wrote:
> > Though, did I get the right impression that NTFS generates lots of
> > extents for small writes even when nothing else is running?
>
> The fragmentation on NTFS was a problem even when nothing else was running
> on the server.  The preallocation patch made all the difference on NTFS and
> cygwin.  In that world it is a must have since it increases performance on
> the reads by orders of magnitude while not impacting the write-side since
> the cygwin posix_fallocate is very efficient.

Was that simply due to writing too-small block to NTFS?  In other
words, would increasing the size of write() calls have fixed it
instead, without leaving allocated but unused disk space in the case
of a user-abort with --partial, --partial-dir or --inplace?

-- Jamie