Hi!
I am currently trying out kernel 2.6.0test5.1.36 (the one from the
Redhat site). After patching in the latest QLogic FibreChannel drivers
(8.0.0.4) and running performance tests I was wondering about the
results. The machine consists of two dual channel PCI-X QLogic FC
Controllers and 4 Infortrend diskarrays with ~2TB each. The arrays are
hardpartitioned (inside the arrays) to 512GB chunks and I am currently
striping them together via /dev/md0 with 2TB.
Kernel 2.6.0test5.1.36custom:
Writing (time -p dd if=/dev/zero of=/xine1/zeros bs=1M count=4K)
Real: 11.00
User: 0.02
Sys: 10.60
Reading (time -p dd if=/xine1/zeros of=/dev/null bs=1M count=4K)
Real: 45.15
User: 0.01
Sys: 7.01
That is a bit weird result, isn't it? On the hand-patched 2.4.20-18.9
Kernel with XFS 1.3.0pre4 I'll get much better read performance and
about similar write performance. I checked if there are any issues
regarding the internal log and tried an external one, but not much of a
change with that.
I am not to proficient in using the kernel profiling tools to see where
the performance goes, so maybe someone could give me a hint what to look
for.
Cheers,
Frank...
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Frank Hellmann Optical Art GmbH Waterloohain 7a
Digital Cinema http://www.opticalart.de 22769 Hamburg
frank@xxxxxxxxxxxxx Tel: ++49 40 5111051 Fax: ++49 40 43169199
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