Solution for ORA-03113: end-of-file on communication channel -----

C:\Users\IBM_ADMIN>sqlplus sys/sys as sysdba

SQL*Plus: Release 11.2.0.1.0 Production on Fri Jul 18 15:58:07 2014

Copyright (c) 1982, 2010, Oracle.  All rights reserved.

Connected to an idle instance.

SQL> startup
ORACLE instance started.

Total System Global Area 1653518336 bytes
Fixed Size                  2176288 bytes
Variable Size            1241516768 bytes
Database Buffers          402653184 bytes
Redo Buffers                7172096 bytes
Database mounted.
ORA-03113: end-of-file on communication channel
Process ID: 6772
Session ID: 191 Serial number: 3


CAUSE:
~~~~~~~~~
$ oerr ora 3113
03113, 00000, "end-of-file on communication channel"
// *Cause: The connection between Client and Server process was broken.
// *Action: There was a communication error that requires further investigation.
//          First, check for network problems and review the SQL*Net setup.
//          Also, look in the alert.log file for any errors. Finally, test to
//          see whether the server process is dead and whether a trace file
//          was generated at failure time



SOLUTION:
~~~~~~~~~~~~~~~~~
you need to check your database instance alert log for a likely ORA-07445 error and a trace file name. 

problem will be
#########################################
FLASH_RECOVERY_AREA is FULL
#########################################
You have following choices to free up space from recovery area:
1. Consider changing RMAN RETENTION POLICY. If you are using Data Guard,
   then consider changing RMAN ARCHIVELOG DELETION POLICY.
2. Back up files to tertiary device such as tape using RMAN
   BACKUP RECOVERY AREA command.
3. Add disk space and increase db_recovery_file_dest_size parameter to
   reflect the new space.
4. Delete unnecessary files using RMAN DELETE command. If an operating
   system command was used to delete files, then use RMAN CROSSCHECK and
   DELETE EXPIRED commands.

crosscheck archivelog all;
crosscheck backupset;
crosscheck copy;
delete expired archivelog all;
delete expired backupset;
delete expired copy;


Errors in file c:\app\uk\diag\rdbms\test\test\trace\test_arc2_10680.trc:
ORA-19815: WARNING: db_recovery_file_dest_size of 5242880000 bytes is 100.00% used, and has 0 remaining bytes available.