在FreeBSD下安装mysql5的注意点

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 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, 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-assemblergmakegmake installcd /usr/local/mysqlbin/mysql_install_db --user=mysqlbin/mysqld_safe &
If you notice that configure uses MIT-pthreads, you should read the 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, 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. 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). 
If you have a lot of memory, you should consider rebuilding the kernel to allow MySQL to use more than 512MB of RAM. Take a look at option MAXDSIZ in the LINT config file for more information. 
If you get problems with the current date in MySQL, setting the TZ variable should help.