:The performance is also lower when reading, here are some lines from
:the random read test:
:
:32 4.81 153.94 0.0000 0.0065 0.8895 0.0103
:64 10.59 169.49 0.0000 0.0059 2.5563 0.0085
:128 15.54 124.35 0.0001 0.0080 3.3134 0.0117
:256 29.90 119.61 0.0001 0.0083 2.2407 0.0116
:
:32 6.34 203.13 0.01 4.92 570.37 7.88
:64 11.66 186.58 0.02 5.36 516.09 8.40
:128 20.30 162.41 0.04 6.15 517.97 9.41
:256 34.13 136.54 0.07 7.32 667.05 10.74
:
:This is with a P400, 512 MiB BBWC and a 15k RPM SAS disk.
Yah, that is more in-line with what I would expect. UFS will win
for data-uncached random reads as long as the namespace itself is
cached (fits in UFS's dirhash cache). This is primarily due to
the direct data blocks stored in the inode itself, so there is one
less I/O.
Also, HAMMER's B-Tree tends to get a bit trashed by those tests,
since no cleanup occurs while the test is running. It is probably
storing additional history as well.
-Matt
Matthew Dillon
<[email protected]>
