2.6.4.1 FreeBSD Notes

FreeBSD 4.x is recommended for running MySQL since the thread package is much more integrated.

The easiest and therefore the preferred way to install is to use the mysql-server and mysql-client ports available on http://www.freebsd.org/.

Using these gives you:

• A working MySQL with all optimisations known to work on your version of FreeBSD enabled.
• Automatic configuration and build.
• Startup scripts installed in /usr/local/etc/rc.d.
• Ability to see which files that are installed with pkg_info -L. And to remove them all with pkg_delete if you no longer want MySQL on that machine.

It is recommended you use MIT-pthreads on FreeBSD 2.x and native threads on Versions 3 and up. It is possible to run with native threads on some late 2.2.x versions but you may encounter problems shutting down mysqld.

Unfortunately, certain function calls on FreeBSD are not yet fully thread-safe, most notably the gethostbyname() function, which is used by MySQL to convert host names into IP addresses. Under certain circumstances, the mysqld process will suddenly cause 100% CPU load and will be unresponsive. If you encounter this, try to start up MySQL using the --skip-name-resolve option.

Alternatively, you can link MySQL on FreeBSD 4.x against the LinuxThreads library, which avoids a few of the problems that the native FreeBSD thread implementation has. For a very good comparison of LinuxThreads vs. native threads have a look at Jeremy Zawodny's article "FreeBSD or Linux for your MySQL Server?" at http://jeremy.zawodny.com/blog/archives/000203.html.

The MySQL `Makefile's require GNU make (gmake) to work. If you want to compile MySQL you need to install GNU make first.

Be sure to have your name resolver setup correct. Otherwise, you may experience resolver delays or failures when connecting to mysqld.

Make sure that the localhost entry in the `/etc/hosts' file is correct (otherwise, you will have problems connecting to the database). The `/etc/hosts' file should start with a line:

127.0.0.1       localhost localhost.your.domain

The recommended way to compile and install MySQL on FreeBSD with gcc (2.95.2 and up) is:

CC=gcc CFLAGS="-O2 -fno-strength-reduce" \
CXX=gcc CXXFLAGS="-O2 -fno-rtti -fno-exceptions -felide-constructors \
-fno-strength-reduce" \
./configure --prefix=/usr/local/mysql --enable-assembler
gmake
gmake install
./scripts/mysql_install_db
cd /usr/local/mysql
./bin/mysqld_safe &

If you notice that configure will use MIT-pthreads, you should read the MIT-pthreads notes. See section 2.3.6 MIT-pthreads Notes.

If you get an error from make install that it can't find `/usr/include/pthreads', configure didn't detect that you need MIT-pthreads. This is fixed by executing these commands:

shell> rm config.cache
shell> ./configure --with-mit-threads

FreeBSD is also known to have a very low default file handle limit. See section A.2.17 File Not Found. Uncomment the ulimit -n section in mysqld_safe or raise the limits for the mysqld user in /etc/login.conf (and rebuild it with cap_mkdb /etc/login.conf). Also be sure you set the appropriate class for this user in the password file if you are not using the default (use: chpass mysqld-user-name). See section 4.7.2 mysqld_safe, The Wrapper Around mysqld.

If you have a lot of memory you should consider rebuilding the kernel to allow MySQL to take more than 512M of RAM. Take a look at option MAXDSIZ in the LINT config file for more info.

If you get problems with the current date in MySQL, setting the TZ variable will probably help. See section F Environment Variables.

To get a secure and stable system you should only use FreeBSD kernels that are marked -RELEASE.

User Comments

If you're going to use MySQL on FreeBSD at 2 or
more CPU's machine, please note, that MySQL would
use only one CPU.
It's because of FreeBSD cannot optimize threads
between multiple CPUs (this feature should appear
in 5.0).
If you want to get full efficiency of
such system, you should compile MySQL with
LinuxThreads, and all optimization, recomended
below. NB: you SHOULD use FreeBSD 4.4 or later,
since older versions work bugly with
LinuxThreads.

On high volume servers using MySQL with FreeBSD
it is also recommended increasing MAXUSERS (i.e.
basically recompiling/rebuilding your kernel). <a
href="http://www.freebsdforums.org/forums">FreeBSD
Forums</a>

For a guide to securing MySQL on FreeBSD, check
out <a
href="http://www.freebsdforums.org/forums/showthre
ad.php?threadid=835">this</a> informative article!

jeremy zawodny's got a heap of interesting info relative to running mysql on freebsd (4.x). check it out here: http://jeremy.zawodny.com/blog/archives/000203.html

When the DB server encounters many query,
I got these error messages when I upgrade from
MySQL 3.23 to MySQL 4.0.12 on a FreeBSD 4.8-PRERELEASE
I query the database via JDBC with the 3.0.6-stable Java API

It seems that there is no problem when using C API

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ERROR 1030: Got error 12 from table handler

ERROR 1135: Can't create a new thread (errno 35). If you are not out of available memory, you can consult the manual for a possible OS-dependent bug

=== cut ===

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