[Ocfs2-users] OCFS2 v. ext3 performance

[Kevin Hulse]

Brian Long wrote:

>Hello,
>
>While playing with Oracle 10gR2 RAC on OCFS2, we decided to run some
>iozone benchmarks on a single node OCFS2 v. ext3 on the same LUNs.  ext3
>outperforms OCFS2 by 12 - 27% in the tests.
>  
>

You need to go into a bit more detail there. What's the
problem: random reads? random writes? sequential writes?

As long as my latency times for log sync writes don't get
out of hand, I can live with even a frightening degredation
in datafile read/write performance. With a magnified SGA,
I don't plan on doing enough random IO to worry about
random IO performance.

My datafile IO drops dramatically when I add nodes
to my cluster.

>While we have not tested Oracle benchmarks like Swingbench on the two
>filesystems yet, we are worried OCFS2 is going to cause an immediate
>performance hit.
>  
>
Why not just test the app?

I can do wicked things to the cluster interconnect that
bear no resemblance to what actually happens in our app.

>When running iozone to the shared OCFS2 on two nodes, performances gets
>even worse.  This doesn't bode well for running RAC on multiple nodes
>and actually increasing performance vs. a single node on ext3.
>
>Any comments on how we can ensure performance of RAC will scale as
>needed on OCFS2?
>
>/Brian/
>  
>