I'll forward this to a coworker who has a lot of knowledge about the various tools, and has put together a reasonable test bench for our storage.
However, one comment: doing benchmarks is not going to give you what you need to tell the app team that they're hallucinating. Any generic artificial benchmark is not going to tell you which truly perform better for your app, because apps require more than just IOPS. They care about things like file system structure, like the number of files and directories, they care about latency, they care about random IOPS, they care about disk throughput, they care about caching, all of that stuff. And unless your benchmark IS their application running under an actual production load, you're not really going to get an accurate picture of our their application will perform on different types of storage. It's probably worth putting together benchmarks of the filesystem/hardware setup combinations so that you have that data handy, but ultimately, measuring the actual utilization of the storage platform(s) in the production environment plus having ways to measure the delays in the application will probably give you a much more compelling argument. That may require instrumenting the app itself, which can theoretically be done without the devs modifying it but is typically done more easily with their help. As an initial start, have you used anything like SAR or nmon or iostat or the various other tools out there to measure the utilization of the actual systems they're complaining about, especially during a period of time that they've complained about? I'd start there, personally, and see if you see the system waiting on IO or if you see some other resource getting maxed out. Nicholas P.S. It's 1:40 am here, I had been asleep but just woke up briefly and while I was up decided to randomly check email, so I'm not entirely awake or coherent. If I say anything to offend or that just sounds stupid, I'm blaming it on that. ;) On Sat, Feb 27, 2010 at 1:12 AM, Atom Powers <[email protected]> wrote: > I have a wide variety of storage devices, and I suspect most of them > are underutilized. To make the best use of them I'd like to measure > what their actual performance is: disk IOps per second. > > The storage is SATA, SCSI, and iSCSI attached to Linux and/or FreeBSD, > UFS and ext 3 or 4 on a variety of i386 hardware. I'm not especially > interested in which ones /should/ perform better, I want to measure > which ones /do/ perform better. (And so I can tell my applications > team that they are hallucinating when they blame performance on the > file system.) > > What tools can I use to measure disk performance? > > -- > Perfection is just a word I use occasionally with mustard. > --Atom Powers-- > _______________________________________________ > Tech mailing list > [email protected] > http://lopsa.org/cgi-bin/mailman/listinfo/tech > This list provided by the League of Professional System Administrators > http://lopsa.org/ >
_______________________________________________ Tech mailing list [email protected] http://lopsa.org/cgi-bin/mailman/listinfo/tech This list provided by the League of Professional System Administrators http://lopsa.org/
