1). In /etc/my.ini, add

skip-grant-tables

2). mysql -u root -p            (no password required)

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| cacti              |
| gfxpv_database     |
| mysql              |
| test               |
+--------------------+
5 rows in set (0.08 sec)

3). select cacti database

mysql> use cacti;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Database changed

4).  show all tables in cacti database

mysql> show tables;
+---------------------------+
| Tables_in_cacti           |
+---------------------------+
| cdef                      |
| cdef_items                |
| colors                    |
| data_input                |
| data_input_data           |
| data_input_fields         |
| data_local                |
| data_template             |
| data_template_data        |
| data_template_data_rra    |
| data_template_rrd         |
| graph_local               |
| graph_template_input      |
| graph_template_input_defs |
| graph_templates           |
| graph_templates_gprint    |
| graph_templates_graph     |
| graph_templates_item      |
| graph_tree                |
| graph_tree_items          |
| host                      |
| host_graph                |
| host_snmp_cache           |
| host_snmp_query           |
| host_template             |
| host_template_graph       |
| host_template_snmp_query  |
| plugin_config             |
| plugin_db_changes         |
| plugin_hooks              |
| plugin_realms             |
| poller                    |
| poller_command            |
| poller_item               |
| poller_output             |
| poller_reindex            |
| poller_time               |
| rra                       |
| rra_cf                    |
| settings                  |
| settings_graphs           |
| settings_tree             |
| snmp_query                |
| snmp_query_graph          |
| snmp_query_graph_rrd      |
| snmp_query_graph_rrd_sv   |
| snmp_query_graph_sv       |
| user_auth                 |
| user_auth_perms           |
| user_auth_realm           |
| user_log                  |
| version                   |
+---------------------------+
52 rows in set (0.00 sec)

5). select all user in the user_auth table(cacti database)

mysql> select * from user_auth;
+----+----------+----------------------------------+-------+---------------+----------------------+-----------+-----------+--------------+----------------+------------+---------------+--------------+--------------+------------------------+---------+
| id | username | password                         | realm | full_name     | must_change_password | show_tree | show_list | show_preview | graph_settings | login_opts | policy_graphs | policy_trees | policy_hosts | policy_graph_templates | enabled |
+----+----------+----------------------------------+-------+---------------+----------------------+-----------+-----------+--------------+----------------+------------+---------------+--------------+--------------+------------------------+---------+
|  1 | admin    | e10adc3949ba59abbe56e057f20f883e |     0 | Administrator |                      | on        | on        | on           | on             |          1 |             1 |            1 |            1 |                      1 | on      |
|  3 | guest    | 43e9a4ab75570f5b                 |     0 | Guest Account | on                   | on        | on        | on           | on             |          3 |             1 |            1 |            1 |                      1 |         |
+----+----------+----------------------------------+-------+---------------+----------------------+-----------+-----------+--------------+----------------+------------+---------------+--------------+--------------+------------------------+---------+
2 rows in set (0.00 sec)

6). update "guest" account with password "guest"

mysql> update user_auth set password=PASSWORD(‘guest‘) where username=‘guest‘;
Query OK, 1 row affected (0.00 sec)
Rows matched: 1  Changed: 1  Warnings: 0

mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)

mysql> flush privileges;

Query OK, 0 rows affected (0.00 sec)

mysql> update user_auth set password=PASSWORD(‘admin‘) where username=‘admin‘;
Query OK, 1 row affected (0.00 sec)
Rows matched: 1  Changed: 1  Warnings: 0

mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)

still not working!!!!!!!!!!!!!!!!!