Messages in this thread |  | | Date | Tue, 13 Nov 2001 15:29:13 +0100 (CET) | From | Roy Sigurd Karlsbakk <> | Subject | Tuning Linux for high-speed disk subsystems |
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Hi all
After some testing at Compaq's lab in Oslo, I've come to the conclusion that Linux cannot scale higher than about 30-40MB/sec in or out of a hardware or software RAID-0 set with several stripe/chunk sizes tried out. The set is based on 5 18GB 10k disks running SCSI-3 (160MBps) alone on a 32bit/33MHz PCI bus.
After speking to the storage guys here, I was told the problem generally was that the OS should send the data requests at 256kB block sizes, as the drives (10k) could handle 100 I/O operations per second, and thereby could give a total of (256*100)kB/sec per spindle. When using smaller block sizes, the speed would decrease in a linear fasion.
Does anyone know this stuff good enough to help me how to tune the system? PS: The CPUs were almost idle during the test. Tested file system was ext2.
Regards
roy
-- Roy Sigurd Karlsbakk, MCSE, MCNE, CLS, LCA
Computers are like air conditioners. They stop working when you open Windows.
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