The default location for the MySQL Unix socket is different on Mac OS X and Mac OS X Server depending on the installation type you chose. The default locations by installation are as follows:

To prevent issues, you should either change the configuration of the socket used within your application (for example, changing php.ini), or you should configure the socket location using a MySQL configuration file and the socket option. For more information, see Server Command Options.

You may need (or want) to create a specific mysql user to own the MySQL directory and data. On Mac OS X 10.4 and lower you can do this by using the Netinfo Manager application, located within the Utilities folder within the Applications folder. On Mac OS X 10.5 and later you can do this through the Directory Utility. From Mac OS X 10.5 and later (including Mac OS X Server 10.5) the mysql should already exist. For use in single user mode, an entry for _mysql (note the underscore prefix) should already exist within the system /etc/passwd file.

Due to a bug in the Mac OS X package installer, you may see this error message in the destination disk selection dialog:

You cannot install this software on this disk. (null)

If this error occurs, simply click the Go Back button once to return to the previous screen. Then click Continue to advance to the destination disk selection again, and you should be able to choose the destination disk correctly. We have reported this bug to Apple and it is investigating this problem.

Because the MySQL package installer installs the MySQL contents into a version and platform specific directory, you can use this to upgrade and migrate your database between versions. You will need to either copy the data directory from the old version to the new version, or alternatively specify an alternative datadir value to set location of the data directory.

You might want to add aliases to your shell's resource file to make it easier to access commonly used programs such as mysql and mysqladmin from the command line. The syntax for bash is:

alias mysql=/usr/local/mysql/bin/mysql
alias mysqladmin=/usr/local/mysql/bin/mysqladmin

For tcsh, use:

alias mysql /usr/local/mysql/bin/mysql
alias mysqladmin /usr/local/mysql/bin/mysqladmin

Even better, add /usr/local/mysql/bin to your PATH environment variable. You can do this by modifying the appropriate startup file for your shell. For more information, see Invoking MySQL Programs.

After you have copied over the MySQL database files from the previous installation and have successfully started the new server, you should consider removing the old installation files to save disk space. Additionally, you should also remove older versions of the Package Receipt directories located in /Library/Receipts/mysql-VERSION.pkg.