RMAN (missing .arc file)

[BeefStu]

Alternative one:

ALLOCATE CHANNEL FOR MAINTENANCE DEVICE TYPE DISK;
CHANGE ARCHIVELOG ALL CROSSCHECK;

Alternative two:

  BACKUP
    FORMAT ...etc...
    ARCHIVELOG ALL DELETE INPUT SKIP INACCESSIBLE;

This will be a one time run correct?
run
{
ALLOCATE CHANNEL FOR MAINTENANCE DEVICE TYPE DISK;
CHANGE ARCHIVELOG ALL CROSSCHECK;
}