ORA-09945: Unable to initialize the audit trail file

Cause: There is no available space for Oracle. audit_trail_dest are full.

Action: Clear some file or allocate space for Oracle database.

SQL> conn /as sysdba
Connected to an idle instance.
SQL> startup;
ORACLE instance started.

Total System Global Area 1119043584 bytes
Fixed Size                  2227624 bytes
Variable Size             838861400 bytes
Database Buffers          268435456 bytes
Redo Buffers                9519104 bytes
Database mounted.
ORA-09945: Unable to initialize the audit trail file
Linux-x86_64 Error: 28: No space left on device
SQL> EXIT
Disconnected from Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 - 64bit Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options
[oracle@OEL64BN1 ~]$ df -k
Filesystem           1K-blocks      Used Available Use% Mounted on
/dev/sda3             17545020   2940900  13712884  18% /
tmpfs                  1154528    710572    443956  62% /dev/shm
/dev/sda1             25803068  24492340         8 100% /u01
[oracle@OEL64BN1 ~]$