select @@global.innodb_use_fallocate; @@global.innodb_use_fallocate 0 select @@session.innodb_use_fallocate; ERROR HY000: Variable 'innodb_use_fallocate' is a GLOBAL variable show global variables like 'innodb_use_fallocate'; Variable_name Value innodb_use_fallocate OFF show session variables like 'innodb_use_fallocate'; Variable_name Value innodb_use_fallocate OFF select * from information_schema.global_variables where variable_name='innodb_use_fallocate'; VARIABLE_NAME VARIABLE_VALUE INNODB_USE_FALLOCATE OFF select * from information_schema.session_variables where variable_name='innodb_use_fallocate'; VARIABLE_NAME VARIABLE_VALUE INNODB_USE_FALLOCATE OFF set global innodb_use_fallocate=1; ERROR HY000: Variable 'innodb_use_fallocate' is a read only variable set session innodb_use_fallocate=1; ERROR HY000: Variable 'innodb_use_fallocate' is a read only variable