On restoring a control file to a database started in nomount, and listener up:
ORA-19870 error reading backup pieceThis error is pretty cut and dried. Either the file path does not exist, or the oracle user doesn't own/have permissions to create the file.
ORA-19504 failed to create file
ORA-27040 file create error, unable to create file.
on restoring a database to a new host with the control file restored, database in nomount, and listener up:
Failure of recover command at
ORA-01013 user requested cancel of current operation
This error could be much more clear. It can be caused by an open connection to the database. Since you're already restoring the database, the easiest way to remedy is to shutdown the database, then startup nomount, and make sure you exit your session before re-running from RMAN.