On Sun, Dec 30, 2007 at 02:18:31PM +0100, Kris Kennaway wrote: > Gergely CZUCZY wrote: > >On Sat, Dec 01, 2007 at 12:22:34PM -1000, Jeff Roberson wrote: > >>On Sat, 1 Dec 2007, Gergely CZUCZY wrote: > >> > >>>On Sat, Dec 01, 2007 at 04:06:55PM -0500, Mike Tancsa wrote: > >>>>At 03:56 PM 12/1/2007, Gergely CZUCZY wrote: > >>>>>I don't quite understand the question. It's the very same box, with > >>>>>a dualboot configuration. > >>>>Fire up the 3ware controller's RAID management software and make sure the > >>>>same write caching strategy is set for FreeBSD and Linux. > >>>>The > >>>>driver my default to different values. > >>>> > >>>>i.e. under "controller settings" make sure "write cache" and "queuing" > >>>>are the same values for linux and freebsd. > >>>Let's get back to this on monday. I'm at home now, and the > >>>box is at me workplace, still running a test (i can't reboot it). > >>Also, can you verify with a read-only test to see where it's at? I have > >>not tested writes with that many threads. I notice mysql > >>goes much faster with a fresh table too. So can you blow away and recreate > >>the sysbench tables and then do read-only? If that is > >>much slower we'll know there is some configuration problem or similar. > >It will all be available here: > >http://phoemix.harmless.hu/mysql/ > > Hi, > > Sorry for the late reply, I was on vacation. I have a couple of comments > about this: > > * You are using some very old mysql versions and trying to compare between > diferent versions. New minor releases in the 5.0 series had > very different performance, and you really need to be using at least 5.0.45 > (I didn't notice a performance change between 5.0.45 and > 5.0.51 but there was a big improvement in every release up to .45. In > addition, versions older than (I think) .37 have serious > performance bugs). > > I appreciate that you might be constrained by local requirements, but it's > really not meaningful to compare different mysql versions if > your goal is to study OS performance. It'd be a PITA to install the both versions. Maybe now, that the ports freeze is over, i can do something. But honestly, every mysql version was faster on linux, than eny on FreeBSD, even the .22 one was faster. We start work on Jan02, I will see what can I do.
> > * What database engine are you using? I have only tested with innodb but > maybe you are using myisam? Please provide your exact > sysbench command lines. MyISAM, of course. InnoDB is not any good with replication, and we need backup. > * Compare to my config file here: > > http://people.freebsd.org/~kris/scaling/my.cnf > > The default mysql config has very poor performance for innodb (you need at > least innodb_thread_concurrency = 0 to disable some mysql > brain-death). Maybe tuning is required for myisam also. > > * Also make sure you are using identical config settings on the two systems. http://phoemix.harmless.hu/mysql/ verify yourself. Only the paths are updated, but the main parameters are just the same. > * With the above, please compare read-only mode also (I think Jeff already > asked you about this but I didnt see a reply). That will > allow us to calibrate what is going on. http://phoemix.harmless.hu/mysql/ro-all.png The graph is mistitled as Read-write, but it's a readonly test. Sincerely, Gergely Czuczy mailto: [EMAIL PROTECTED] -- Weenies test. Geniuses solve problems that arise.
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