ORA-02820: Unable to write the requested number of blocks
Cause : A server could not write the requested amount of data out to disk. The disk may have run out of space.
Action - How to fix it : DBA Scripts :: www.high-oracle.com/scripts
Check the UNIX error number.
Well, the reason for above error is that i have taken the above script from a 11g database and running it on 10g database. 11g has bring some changes in password management. Below code is executed on 11g and user created successfully, which is expected result.