On Aug 11, 2008, at 5:17 AM, Henrik wrote:
OK, changed the SAS RAID 10 to RAID 5 and now my random writes are
handing 112 MB/ sek. So it is almsot twice as fast as the RAID10
with the same disks. Any ideas why?
Is the iozone tests faulty?
does IOzone disable the os caches?
If not you need to use a size of 2xRAM for true results.
regardless - the test only took 10 seconds of wall time - which isn't
very long at all. You'd probably want to run it longer anyway.
iozone -e -i0 -i1 -i2 -i8 -t1 -s 1000m -r 8k -+u -F /database/iotest
Children see throughput for 1 random writers = 112074.58 KB/sec
Parent sees throughput for 1 random writers = 111962.80 KB/sec
Min throughput per process = 112074.58 KB/sec
Max throughput per process = 112074.58 KB/sec
Avg throughput per process = 112074.58 KB/sec
Min xfer = 1024000.00 KB
CPU utilization: Wall time 9.137 CPU time 0.510 CPU
utilization 5.58 %
--
Jeff Trout <jeff@xxxxxxxxxxxxx>
http://www.stuarthamm.net/
http://www.dellsmartexitin.com/
