Can't create/write to file '/var/tmp/#sql-temptable-42f-28a3aa-7.MAI' (Errcode: 28 "No space left on device")

/var/www/html/biolucida/database/base/databaseconnection.php:223 __call( );
/var/www/html/biolucida/database/base/databaseconnection.php:189 query( );
/var/www/html/biolucida/database/base/project.php:583 fetchRows( );
/var/www/html/biolucida/include/collectionlist.php:85 getTrackedDirectories( );
/var/www/html/biolucida/include/container/imagebrowse_container.php:59 selectionValues( );
/var/www/html/biolucida/include/container/imagebrowse_container.php:967 getSessionSelection( );
/var/www/html/biolucida/include/page.php:131 process( );
/var/www/html/biolucida/htdocs/index.php:41 generate( );