From that same MySQL manual page, I disable the InnoDB engine,
db configuration setprop mysqld InnoDB disabled
expand-template /etc/my.cnf
sv t /service/mysqld
And now the error returned when I manually run mysql-dump-tables is,
ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (2)
From the manual page again, I restore the InnoDB tables,
db configuration setprop mysqld InnoDB enabled
expand-template /etc/my.cnf
sv t /service/mysqld
and once again I get error 1044.
mysqldump: Got error: 1044: Access denied for user 'root'@'localhost' to database 'information_schema' when using LOCK TABLES
I tried scheduling a backup through the server-manager after disabling InnoDB and I am getting reports again about successful backups. But, the user preferences in the email are not available. I get a little report at the top of the mail display,
The preferences backend is currently unavailable and your preferences have not been loaded. You may continue to use the system with default settings.
So disabling InnoDB appears to disable the default settings in Horde. Horde is still otherwise working OK.
It looks as though InnoDB might play a role. How to fix the user preferences in Horde? What else in SME uses the InnoDB tables that might be effected?