According to the QA page for libapache-mod-auth-mysql, it was removed From etch because of failed to build From source against apache2.2. You could work around the missing package with libapache2-mod-auth-pam and libpam-mysql

我个人推荐这个方法，100%成功。http://ubuntuforums.org/showpost.php?p=1846046&postcount=18

Update1:
我测试了很久 libapache2-mod-auth-pam，想在apache2整合MySql认证，结果，orz
https://answers.launchpad.net/ubuntu/+source/libapache2-mod-auth-pam/+question/10853

mod_auth_pam is a module that requires access to one's system password file. http://pam.sourceforge.net/mod_auth_pam/ recommends the use of mod_authnz_external as mod_auth_pam is no longer developed/supported

汗啊汗，我辛苦配置了3周的SVN+DAV+Apache2+MySQL认证由光荣的失败喽，现在开始研究 mod_authnz_external

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