On May 16, 2011, at 1:06 PM, John Rouillard wrote:
that is a #define in pgiosim.c
So which is a better test, modifying the #define to allow specifying
200-300 1GB files, or using 64 files but increasing the size of my
files to 2-3GB for a total bytes in the file two or three times the
memory in my server (96GB)?
I tend to make 10G chunks with dd and run pgiosim over that.
dd if=/dev/zero of=bigfile bs=1M count=10240
the -w param to pgiosim has it rewrite blocks out as it runs. (it is
a percentage).
Yup, I was running with that and getting low enough numbers, that I
switched to pure read tests. It looks like I just need multiple
threads so I can have multiple reads/writes in flight at the same
time.
Yep - you need multiple threads to get max throughput of your io.
--
Jeff Trout <jeff@xxxxxxxxxxxxx>
http://www.stuarthamm.net/
http://www.dellsmartexitin.com/
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