Oracle won't start due to FRA full

Happens a lot on VM environments which are starved of disk space.

The common error is

ORA-19815: WARNING: db_recovery_file_dest_size of 214748364800 bytes is 100.00% used, and has 0 remaining bytes available.

You can't use ALTER TABLE to change the parameter, because the DB won't start. So..

sqlplus / as sysdba

create pfile from spfile;

edit the parameter db_recovery_file_dest_size (make it bigger so that the DB can start, hopefully you still have enough disk space), then

create spfile from pfile;

startup

Also, delete the contents of the FRA (via operating system) then do the following:

rman nocatalog target /

crosscheck archivelog all
delete expired archivelog all