FreeBSD 4.x or newer is recommended for running MySQL, because the thread package is much more integrated. To get a secure and stable system, you should use only FreeBSD kernels that are marked -RELEASE.

The easiest (and preferred) way to install MySQL is to use the mysql-server and mysql-client ports available at http://www.freebsd.org/. Using these ports gives you the following benefits:

It is recommended you use MIT-pthreads on FreeBSD 2.x, and native threads on FreeBSD 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, this includes the gethostbyname() function, which is used by MySQL to convert hostnames into IP addresses. Under certain circumstances, the mysqld process suddenly causes 100% CPU load and is unresponsive. If you encounter this problem, try to start 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 versus native threads, see Jeremy Zawodny's article FreeBSD or Linux for your MySQL Server? at http://jeremy.zawodny.com/blog/archives/000697.html.

Known problem when using LinuxThreads on FreeBSD is:

The MySQL build process requires GNU make (gmake) to work. If GNU make is not available, you must install it first before compiling MySQL.

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
cd /usr/local/mysql
bin/mysql_install_db --user=mysql
bin/mysqld_safe &

If you notice that configure uses MIT-pthreads, you should read the MIT-pthreads notes. See Section 2.4.15.5, “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. To fix this problem, remove config.cache, and then re-run configure with the --with-mit-threads option.

Be sure that your name resolver setup is correct. Otherwise, you may experience resolver delays or failures when connecting to mysqld. Also make sure that the localhost entry in the /etc/hosts file is correct. The file should start with a line similar to this:

127.0.0.1       localhost localhost.your.domain

FreeBSD is known to have a very low default file handle limit. See Section B.1.2.18, “'File' Not Found and Similar Errors”. Start the server by using the --open-files-limit option for 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 that 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 4.3.2, “mysqld_safe — MySQL Server Startup Script”.

FreeBSD limits the size of a process to 512MB, even if you have much more RAM available on the system. So you may get an error such as this:

Out of memory (Needed 16391 bytes)

In current versions of FreeBSD (at least 4.x and greater), you may increase this limit by adding the following entries to the /boot/loader.conf file and rebooting the machine (these are not settings that can be changed at run time with the sysctl command):

kern.maxdsiz="1073741824" # 1GB
kern.dfldsiz="1073741824" # 1GB
kern.maxssiz="134217728" # 128MB

For older versions of FreeBSD, you must recompile your kernel to change the maximum data segment size for a process. In this case, you should look at the MAXDSIZ option in the LINT config file for more information.

If you get problems with the current date in MySQL, setting the TZ variable should help. See Section 2.4.20, “Environment Variables”.

To compile on NetBSD, you need GNU make. Otherwise, the build process fails when make tries to run lint on C++ files.

On OpenBSD 2.5, you can compile MySQL with native threads with the following options:

CFLAGS=-pthread CXXFLAGS=-pthread ./configure --with-mit-threads=no

If you get the following error when compiling MySQL, your ulimit value for virtual memory is too low:

item_func.h: In method
`Item_func_ge::Item_func_ge(const Item_func_ge &)':
item_func.h:28: virtual memory exhausted
make[2]: *** [item_func.o] Error 1

Try using ulimit -v 80000 and run make again. If this doesn't work and you are using bash, try switching to csh or sh; some BSDI users have reported problems with bash and ulimit.

If you are using gcc, you may also use have to use the --with-low-memory flag for configure to be able to compile sql_yacc.cc.

If you get problems with the current date in MySQL, setting the TZ variable should help. See Section 2.4.20, “Environment Variables”.

Upgrade to BSD/OS 3.1. If that is not possible, install BSDIpatch M300-038.

Use the following command when configuring MySQL:

env CXX=shlicc++ CC=shlicc2 \
./configure \
    --prefix=/usr/local/mysql \
    --localstatedir=/var/mysql \
    --without-perl \
    --with-unix-socket-path=/var/mysql/mysql.sock

The following is also known to work:

env CC=gcc CXX=gcc CXXFLAGS=-O3 \
./configure \
    --prefix=/usr/local/mysql \
    --with-unix-socket-path=/var/mysql/mysql.sock

You can change the directory locations if you wish, or just use the defaults by not specifying any locations.

If you have problems with performance under heavy load, try using the --skip-thread-priority option to mysqld. This runs all threads with the same priority. On BSDI 3.1, this gives better performance, at least until BSDI fixes its thread scheduler.

If you get the error virtual memory exhausted while compiling, you should try using ulimit -v 80000 and running make again. If this doesn't work and you are using bash, try switching to csh or sh; some BSDI users have reported problems with bash and ulimit.

BSDI 4.x has some thread-related bugs. If you want to use MySQL on this, you should install all thread-related patches. At least M400-023 should be installed.

On some BSDI 4.x systems, you may get problems with shared libraries. The symptom is that you can't execute any client programs, for example, mysqladmin. In this case, you need to reconfigure not to use shared libraries with the --disable-shared option to configure.

Some customers have had problems on BSDI 4.0.1 that the mysqld binary after a while can't open tables. This occurs because some library/system-related bug causes mysqld to change current directory without having asked for that to happen.

The fix is to either upgrade MySQL to at least version 3.23.34 or, after running configure, remove the line #define HAVE_REALPATH from config.h before running make.

Note that this means that you can't symbolically link a database directories to another database directory or symbolic link a table to another database on BSDI. (Making a symbolic link to another disk is okay).