Xfs

http://events.linuxfoundation.org/slides/2010/linuxcon2010_wheeler.pdf PDF slides that show what happens if you create a file system with one billion (10**9 ) files

http://www.jejik.com/articles/2008/04/benchmarking_linux_filesystems_on_software_raid_1/ notes on 3ware 9550XS vs md RAID1 for various filesystems on Linux