In the ext4-devel discussion, I asked about placement of the reserved
blocks. Placement at the beginning of the group showed at worst
marginally less performance and in some cases better performance.
I suspect putting the reserved blocks at the beginning of the group
would have a better long-term effect on performance because they are
not in the middle of large contiguous allocations in the middle of
the group.
Cheers, Andreas
--
Andreas Dilger
Sr. Software Engineer, Lustre Group
Sun Microsystems of Canada, Inc.
-