MySQL performance concern

[Jeremy Chadwick]

On Sat, Oct 02, 2010 at 01:18:20PM -0700, Rumen Telbizov wrote:
> Hello everyone,
> 
> Here's the requested information below:

The tunings between your Linux and FreeBSD instances differ severely,
and some of the variables don't even exist any longer (example:
table_cache is now known as table_open_cache as of MySQL 5.1.3, and
probably key_buffer vs. key_buffer_size too).

Can you please rule out MySQL tunings being responsible for the problem?

Here are your configuration bits, more sanely written:

				FreeBSD		Linux
--------------------------	--------------	------------------
MySQL version			5.1.51		5.1.50
--------------------------	--------------	------------------

my.cnf tuning			FreeBSD		Linux
--------------------------	--------------	------------------
key_buffer_size			   8 GB		????
key_buffer			????		   4 GB
max_allowed_packet		  16 MB		   1 MB
table_open_cache		2048		????
table_cache			????		  64
sort_buffer_size		  64 MB		 512 KB
read_buffer_size		   8 MB		 256 KB
read_rnd_buffer_size		  16 MB		 512 KB
net_buffer_length		????		   8 KB
myisam_sort_buffer_size		 256 MB		   8 MB
thread_cache_size		  64		????
query_cache_size		  32 MB		????
thread_concurrency		   8		????
max_heap_table_size		   6 GB		   6 GB
--------------------------	--------------	------------------

Can you also please provide "top" output for the mysqld process on
FreeBSD?

>  * As for the ZFS. Here's the pool configuration:

If you move things to UFS2, does the problem disappear?

You might not be seeing any disk I/O on the filesystem with gstat
because ZFS ARC could have all of the data in it.

-- 
| Jeremy Chadwick                                   jdc at parodius.com |
| Parodius Networking                       http://www.parodius.com/ |
| UNIX Systems Administrator                  Mountain View, CA, USA |
| Making life hard for others since 1977.              PGP: 4BD6C0CB |