Messages in this thread | | | Date | Mon, 24 Nov 2003 02:05:34 -0800 (PST) | From | Martin Knoblauch <> | Subject | Re: RAID-0 read perf. decrease after 2.4.20 |
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>Hello All! > >Has anyone else experienced a drastic drop in read performance on >software >RAID-0 with post 2.4.20 kernels? We have a few Athlon XP's here at our >lab with double IDE disks on different channels set up as RAID-0. Some >bonnie++ benchmark results with various kernels, on the same machine >(Athlon XP 2400+, 2 GHz, 1.5 GB RAM, VIA chipset, 2*Maxtor 120 GB >6Y060L0): >write read >2.4.20-ac1: 88,000 135,000 K/sec >2.4.21-pre7: 93,000 75,000 >2.4.22-ac4: 94,000 82,000
Hi,
I can attest a similar drop in read performance on a IA64 box going from a 2.4.19ish kernel to 2.4.22. In our setup the RAID0 is LVM, not MD.The RAID is used a a scratch device for a out-of-core finite element program (NASTRAN).
The setup is some 20 disks on 4 controllers. "iozone" read/reread Performance went from about 400MB/sec to 260 MB/sec, while write went up a notch. Unfortunatelly the read performance is more important for the application in question.
Due to the fact that I have no controll over the use of the system I cannot make any experiments to find out what killed performance. Sorry :-(
Martin
===== ------------------------------------------------------ Martin Knoblauch email: knobi@knobisoft.de or knobi@rocketmail.com www: http://www.knobisoft.de
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