FreeBSD MySQL still WAY slower than Linux

[Michael Schuh]

Hi Oliver,

2005/6/22, Oliver Fromme <olli at lurza.secnetix.de>:
> Michael Schuh <michael.schuh at gmail.com> wrote:
>  > now i have another question, if i use the same Os in 2 versions
>  > (RELENG_4, RELENG_5) can i hope that the tests are made on the same
>  > part of disk?
> 
> <yoda>
> Hope you always can.  But rely on it you should not.
> </yoda>
> ;-)
> 
That's right. :-D

>  >  or in other words can an dd on the two OS' es so much different
>  > because they use an
>  > totally other part of disk? I think no, the strategie from dd under
>  > one OS should not be changed if the OS-Version has changed.
> 
> It's not the dd which decides where to put the file, it's
> the filesystem code.  And yes, there can be differences
> between RELENG_4 and RELENG_5.  In particular, in RELENG_5
> you have UFS2, not the old UFS.  There have always been
> changes to the FS code, for example I remember that the
> allocation of directories has changed some time ago to
> improve metadata performance for large trees (known as
> "dirpref").
> 
> As I said:  The only way to make sure you hit the same
> physical place on the disk is to use a raw partition, not
> a file on some filesystem.
> 

Yes i have that understand.
And that was the reason why i make in future these tests new
with an raw-partition on the same part of disk. so that i never must hope,
so i become knowledge and i know the facts :-D

> Note that even small differences in the placement of the
> file can have a noticeable effect on the speed.  Apart
> from the speed differences of the disk cylinders, it can
> also happen that the file is allocated in a non-contiguous
> way, especially if it is large and the filesystem already
> contains a lot of files, and/or had a lot of write+delete
> operations previously (i.e. causing fragmentation).
> 

yes this is also clear for me, but in my case, it was only a small
disk (8GB) and it has only the OS, nothing more, nothing less.

And as i made these tests, i have all the performance for me and my
OS. *grrrrr* i be the master of disaster.......... *lol*
We should have all more humor.......the life it's more funny......

>  > the part with serial IO related to database-performance have i
>  > understand, but i quests me have the others understand
>  > my meanings?
> 
i must hope so :-D, i can not sure

> That I don't know.
> 
> Best regards
>    Oliver
> 
> --
> Oliver Fromme, secnetix GmbH & Co KG, Oettingenstr. 2, 80538 München
> Any opinions expressed in this message may be personal to the author
> and may not necessarily reflect the opinions of secnetix in any way.
> 
> "anyone new to programming should be kept as far from C++ as
> possible;  actually showing the stuff should be considered a
> criminal offence" -- Jacek Generowicz
> 
thank you for your suggestions

best regards

Michael Schuh