O Omeka encontrou um erro

Zend_Db_Statement_Mysqli_Exception

Mysqli statement execute error : Disk full (/tmp/#sql_6e4_0); waiting for someone to free some space...

#0 /var/www/edufes/omeka/application/libraries/Zend/Db/Statement.php(303): Zend_Db_Statement_Mysqli->_execute(Array)
#1 /var/www/edufes/omeka/application/libraries/Zend/Db/Adapter/Abstract.php(480): Zend_Db_Statement->execute(Array)
#2 /var/www/edufes/omeka/application/libraries/Zend/Db/Adapter/Abstract.php(737): Zend_Db_Adapter_Abstract->query('?        SELECT...', Array)
#3 [internal function]: Zend_Db_Adapter_Abstract->fetchAll('?        SELECT...')
#4 /var/www/edufes/omeka/application/libraries/Omeka/Db.php(79): call_user_func_array(Array, Array)
#5 /var/www/edufes/omeka/plugins/CollectionTree/models/Table/CollectionTree.php(135): Omeka_Db->__call('fetchAll', Array)
#6 /var/www/edufes/omeka/plugins/CollectionTree/models/Table/CollectionTree.php(135): Omeka_Db->fetchAll('?        SELECT...')
#7 /var/www/edufes/omeka/plugins/CollectionTree/models/Table/CollectionTree.php(317): Table_CollectionTree->cacheCollections()
#8 /var/www/edufes/omeka/plugins/CollectionTree/views/helpers/CollectionTreeFullList.php(23): Table_CollectionTree->getRootCollections()
#9 [internal function]: CollectionTree_View_Helper_CollectionTreeFullList->collectionTreeFullList()
#10 /var/www/edufes/omeka/application/libraries/Zend/View/Abstract.php(350): call_user_func_array(Array, Array)
#11 /var/www/edufes/omeka/plugins/CollectionTree/controllers/IndexController.php(18): Zend_View_Abstract->__call('collectionTreeF...', Array)
#12 /var/www/edufes/omeka/plugins/CollectionTree/controllers/IndexController.php(18): Omeka_View->collectionTreeFullList()
#13 /var/www/edufes/omeka/application/libraries/Zend/Controller/Action.php(516): CollectionTree_IndexController->indexAction()
#14 /var/www/edufes/omeka/application/libraries/Zend/Controller/Dispatcher/Standard.php(308): Zend_Controller_Action->dispatch('indexAction')
#15 /var/www/edufes/omeka/application/libraries/Zend/Controller/Front.php(954): Zend_Controller_Dispatcher_Standard->dispatch(Object(Zend_Controller_Request_Http), Object(Zend_Controller_Response_Http))
#16 /var/www/edufes/omeka/application/libraries/Zend/Application/Bootstrap/Bootstrap.php(101): Zend_Controller_Front->dispatch()
#17 /var/www/edufes/omeka/application/libraries/Zend/Application.php(366): Zend_Application_Bootstrap_Bootstrap->run()
#18 /var/www/edufes/omeka/application/libraries/Omeka/Application.php(79): Zend_Application->run()
#19 /var/www/edufes/omeka/index.php(23): Omeka_Application->run()
#20 {main}