удалить zabbix-server-mysql

что значит «{u}» в названии пакета?

http://algebraicthunk.net/~dburrows/blog/entry/aptitude-0.4.10-released/

When run in command-line mode, instead of displaying many separate and sometimes duplicative groups of packages (e.g.: installed, auto-installed, auto-installed in a light cream sauce, etc), aptitude displays packages in a few exclusive categories and uses tags (like the existing «purge» tag) to provide more state information. For instance:

    $ aptitude -s install wesnoth
    The following NEW packages will be installed:
      wesnoth wesnoth-data{a} wesnoth-music{a}
    $ aptitude -s remove freeciv-data
        (... dependency resolution ...)
    The following packages will be REMOVED:
      freeciv-client-gtk{a} freeciv-data freeciv-server{a} ggzcore-bin{u}
      libggz-gtk1{u} libggz2{u} libggzcore9{u} libggzdmod6{u} libggzmod4{u}

Here {a} indicates that a package was automatically installed or removed, and {u} indicates that a package is being removed because it is unused. Hopefully this will be less confusing than the old format.

mysql-server случайно не был установлен вместе с забиксом?

нет... рискнул удалил: был удален пакет mysql-server, а mysql-server-5.1 и mysql-server-core-5.1 остались...

т.е. стало:

aptitude search ~imysql-server
i   mysql-server-5.1
i A mysql-server-core-5.1 

mysql остался, базы не пострадали..