Default user and passwd for mysql

i found that mysql is installed on my wd cloud device ,

but i don’t know the default passwd and user name, who can help me?

root@WDMyCloud root # mysql -u admin -p
Enter password:
ERROR 1045 (28000): Access denied for user ‘admin’@‘localhost’ (using password: NO)

i used the user name root w/o passwd and w/ passwd(the same as ssh ) but both failed



What model of My Cloud do you have? mysql is not installed on the single bay model.