I ran blockbench on a HAMMER partition and on a UFS partition and
    got some rather interesting results.

    I fully expected HAMMER's write performance to be bad compared to UFS,
    because HAMMER is still double-buffering its data.  Indeed, as the
    test began UFS seemed to be outdoing HAMMER.  But as the number of files
    grew and the kernel started to have to recycle vnodes and buffers, UFS's
    performance went completely to hell while HAMMER was able to maintain good
    throughput.  Ths basic blog benchmark creates, reads, and writes around
    20,000 files and goes for a lot of parallelism.

    I don't know why UFS's write performance went to hell.. it pretty much
    died completely after a very promising start.  But even ignoring that
    as some sort of implementation fluke the read performance numbers speak
    for themselves.

    I haven't run bonnie++ yet.  I think UFS still does very well vs HAMMER
    on saturated single-file I/O.

						-Matt


test29# blogbench -d /usr/obj/bench		(HAMMER MOUNT)

Frequency = 10 secs
Scratch dir = [/usr/obj/bench]
Direct I/O: disabled
Spawning 3 writers...
Spawning 1 rewriters...
Spawning 5 commenters...
Spawning 100 readers...
Benchmarking for 30 iterations.
The test will run during 5 minutes.

  Nb blogs   R articles    W articles    R pictures    W pictures    R comments    W comments
        17        90598           894         64890           945         44719          2268
        22        82772           362         63112           348         52860          1002
        32        75915           537         53145           484         49000          1482
        34        86616           188         58819           213         54302           542
        38        85506           179         60253           195         51557           474
        43        73030           441         51141           390         43208          1582
        45        72860           156         51320           226    ...
[ message continues ]

Matthew Dillon wrote:
 >     I ran blockbench on a HAMMER partition and on a UFS partition and
 >     got some rather interesting results.
 >
 >     I fully expected HAMMER's write performance to be bad compared to 
UFS,
 >     because HAMMER is still double-buffering its data.  Indeed, as the
 >     test began UFS seemed to be outdoing HAMMER.  But as the number 
of files
 >     grew and the kernel started to have to recycle vnodes and 
buffers, UFS's
 >     performance went completely to hell while HAMMER was able to 
maintain good
 >     throughput.  Ths basic blog benchmark creates, reads, and writes 
around
 >     20,000 files and goes for a lot of parallelism.
 >
 >     I don't know why UFS's write performance went to hell.. it pretty 
much
 >     died completely after a very promising start.  But even ignoring that
 >     as some sort of implementation fluke the read performance numbers 
speak
 >     for themselves.
 >
 >     I haven't run bonnie++ yet.  I think UFS still does very well vs 
HAMMER
 >     on saturated single-file I/O.

Would be nice to see some UFS benchmarks of FreeBSD, to make sure it's
not an issue with DragonFly's UFS "implementation". Too sad that I don't
have UFS anymore (only ZFS), so I could do it myself. And then, the
benchmark should be done on one and the same machine. But probably it's
wise to wait a few days for benchmarks :)

Regards,

   Michael