On Oct 26, 2007 16:24 -0500, Eric Sandeen wrote: > The resulting file had over 4k extents. > [root@bear-05 ~]# filefrag -v /mnt/test/foobar | grep -i extents > File is stored in extents format > /mnt/test/foobar: 4075 extents found On a related note - we're just putting the finishing touches on the FIEMAP patches for ext4 + e2fsprogs, so that we can get decent looking output from filefrag, and much more efficiently than FIBMAP. > if I don't mount with delalloc: > > mount -t ext4dev -o data=writeback,extents,mballoc /dev/sdb7 /mnt/test > > and run the same dd, I get 229 extents: > > [root@bear-05 ~]# filefrag -v /mnt/test/foobar | grep -i extents > File is stored in extents format > /mnt/test/foobar: 229 extents found One of the issues is that w/o delalloc the mballoc code only gets single-block allocations, so there might be a problem with the interface to mballoc. That might be caused by the fact the patches were changed at one point from delalloc-atop-mballoc to mballoc-atop-delalloc, and something was missed in that conversion. Have you tried O_DIRECT? That is another way to access mballoc w/o using delalloc. Cheers, Andreas -- Andreas Dilger Sr. Software Engineer, Lustre Group Sun Microsystems of Canada, Inc. - To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
