Description:
Manual (http://dev.mysql.com/doc/refman/5.6/en/server-system-variables.html#sysvar_default_storage...) does not explicitly list possible values for the default_storage_engine (even though it's type is listed as "enumeration") and does not explain what storage engine may be set as default.
It seems you can use engine that is available and enabled according to SHOW ENGINES output (all BUT PERFORMANCE_SCHEMA).
How to repeat:
mysql> set global default_storage_engine=something;
ERROR 1286 (42000): Unknown storage engine 'something'
mysql> show engines;
+--------------------+---------+------------------------------------------------
----------------+--------------+------+------------+
| Engine | Support | Comment
| Transactions | XA | Savepoints |
+--------------------+---------+------------------------------------------------
----------------+--------------+------+------------+
| FEDERATED | NO | Federated MySQL storage engine
| NULL | NULL | NULL |
| MRG_MYISAM | YES | Collection of identical MyISAM tables
| NO | NO | NO |
| MyISAM | YES | MyISAM storage engine
| NO | NO | NO |
| BLACKHOLE | YES | /dev/null storage engine (anything you write to
it disappears) | NO | NO | NO |
| CSV | YES | CSV storage engine
| NO | NO | NO |
| MEMORY | YES | Hash based, stored in memory, useful for tempor
ary tables | NO | NO | NO |
| ARCHIVE | YES | Archive storage engine
| NO | NO | NO |
| InnoDB | DEFAULT | Supports transactions, row-level locking, and f
oreign keys | YES | YES | YES |
| PERFORMANCE_SCHEMA | YES | Performance Schema
| NO | NO | NO |
+--------------------+---------+------------------------------------------------
----------------+--------------+------+------------+
9 rows in set (0.32 sec)
mysql> set global default_storage_engine=federated;
ERROR 1286 (42000): Unknown storage engine 'federated'
mysql> set global default_storage_engine=MRG_MYISAM;
Query OK, 0 rows affected (0.00 sec)
mysql> show engines;
+--------------------+---------+------------------------------------------------
----------------+--------------+------+------------+
| Engine | Support | Comment
| Transactions | XA | Savepoints |
+--------------------+---------+------------------------------------------------
----------------+--------------+------+------------+
| FEDERATED | NO | Federated MySQL storage engine
| NULL | NULL | NULL |
| MRG_MYISAM | DEFAULT | Collection of identical MyISAM tables
| NO | NO | NO |
| MyISAM | YES | MyISAM storage engine
| NO | NO | NO |
| BLACKHOLE | YES | /dev/null storage engine (anything you write to
it disappears) | NO | NO | NO |
| CSV | YES | CSV storage engine
| NO | NO | NO |
| MEMORY | YES | Hash based, stored in memory, useful for tempor
ary tables | NO | NO | NO |
| ARCHIVE | YES | Archive storage engine
| NO | NO | NO |
| InnoDB | YES | Supports transactions, row-level locking, and f
oreign keys | YES | YES | YES |
| PERFORMANCE_SCHEMA | YES | Performance Schema
| NO | NO | NO |
+--------------------+---------+------------------------------------------------
----------------+--------------+------+------------+
9 rows in set (0.03 sec)
Suggested fix:
Explain what values are valid and recommended for this variables. In case of 5.6 we have the same problem for default_tmp_storage_engine also.
