Hello, yes random IO is more targetted to Databases. noop, i have the installation always made in the same way, and i have respected the different diskperformace in different disk-parts..... this was the reason for
#cd /; at the beginning of my tests. In the first test i have me shooting self in my foot and i bites me in my ass :-))) my suggestion going more in the direction...first solve all disk(ata) related performace issues, then test the mysql-performaces issues again to secure that you are not lying on an mixing of many problems.... :-) I think this was better then seek around corners that are not so relevant... or the result is not so dramatically.... greetings Michael 2005/6/20, Mark Kirkwood <[EMAIL PROTECTED]>: > Michael Schuh wrote: > > > > > > My results was that RELENG_5 is half as RELENG_4 fast by disk-access > > (ata-related). > > > > I have seen that RELENG_5 with GENERIC Kernel and only modified option > > HZ=2000. > > > > the spread begind with Gentoo (mentoided from me as the slowest, but > > errare humanum est) > > > > Gentoo : 100% time consumption > > RELENG_4: 67% time consumtion > > DrangonFly Rel1.2 69-72% time consumption (i think preemtion) > > RELENG_5 134% time consumtion > > > > these tests are made on physically the same Hardware (real, not equal > > system, same system, same disk, same RAM) with the command: > > > > # cd /; /usr/bin/time dd if=/dev/zero bs=1024 count=1024k of=zerofile; > > > > > > You have shown that sequential IO is slower in RELENG_5 (I think others > have observed this also - check out Google)...However, random IO is > often more important for databases, and RELENG_5 can be faster than > RELENG_4 (try out iozone, it makes testing this easy). > > Also note that if your operating systems are installed in different > parts of the same disk, then this will effect your results too - as some > parts are faster than others. > > With respect to Mysql performance, I would suspect threading or > threading/kernel interaction as the culprit. (That reminds me, I don't > recall seeing the original poster re-doing the tests with 6.0-CURRENT - > that would be interesting). > > cheers > > Mark > > _______________________________________________ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "[EMAIL PROTECTED]"
