FreeBSD MySQL still WAY slower than Linux

[Stephane Raimbault]

On 28-Jun-05, at 1:01 PM, Xin LI wrote:
>>

>
> We care about why MySQL appears to be slower, how to improve the  
> situation,
> and not numbers from poorly done benchmarks which ignored the  
> effect of
> debugging options, version, disk mount options, etc., which is IMHO
> meaningless.
>
> Maybe a key feature of the new FreeBSD installer would be to  
> automatically
> tune the user's system (including kernel and other loader/sysctl  
> tunings)
> according to installed ports :-)
>
> To make benchmarks a help provided to improve FreeBSD, a better  
> start would
> be to run MySQL with profiling options compiled in, to find out the
> bottleneck and report them (maybe with patches if you have some idea).
>
> Cheers,
> -- 
> Xin LI <delphij frontfree net>    http://www.delphij.net/
> See complete headers for GPG key and other information.
>
>



I'm by far not a developer or a programmer, but I am a sysadmin  
running MySQL on FreeBSD 4.x and 5.x   And I am having performance  
problems running FreeBSD 5.4 + SMP with MySQL.  I don't seem to have  
these problems on my other 4.x servers.

The Hardware:

Dell PowerEdge 2850
Dual 2.8 XEON
4Gig of RAM
Raid controller PERC 4/DC
2x 36Gig 10K drives running Raid 1 for the system
4x72Gig 15K drives running raid 0+1 for where to put my mysql innodb  
based database.

The database is about 10Gigs in size all InnoDB tables.

This box is currently setup to slave from the master.  My goal is to  
get the box to replace the master.  Currently it is not used in  
production, so I am free to do what I want to this box.

I'm running MySQL 4.1.12

I noticed a couple things

PAE kernel (no SMP)

System crashed while simply slaving from the master.  The system  
seemed stable doing nothing for 36 hours prior to this.

SMP Kernel

System was stable, however slaving from the master seemed to me VERY  
slow.

GENERIC Kernel

System was stable, and slaving was quite a bit faster.


My Goal, is to provide some information that the real miracle  
workers, the programmers and developers that can contribute to  
FreeBSD help me identify the problems and where they lie and how to  
best go about finding solutions for these problems.

So my question is.  What kind of information can I provide you all to  
help identify the problems that I'm seeing, and quite possibly others  
are seeing.

Xin, you are talking about something regarding profiling of mysql.   
If you can point me in the right direction to setup my box to provide  
the necessary information, I have the time and the will to provide  
the right information so we can move forward in making FreeBSD the  
Operating System we all want it to be.

I also promise to post some usable information for other people  
wanting to setup MySQL on FreeBSD once we have identified where are  
problems lie.  This is probably the best way I, myself can contribute  
back to the FreeBSD Community.

Thank you,
Stephane.