SUMMARY
Oracle Backup fails with file create error
ISSUE
ORA-19504: failed to create file "/usr/bp/mnt/natest/unitrends-full-NATESTxx-20150609-220-1-881946839"
ORA-27040: file create error, unable to create file
Linux-x86_64 Error: 22: Invalid argument
This is caused by the option FILESYSTEMIO_OPTIONS viewable by “show parameter filesystemio_options”
https://docs.oracle.com/cd/B28359_01/server.111/b28320/initparams083.htm#REFRN10061
If this option is set to “directIO” or “setall” configuration, the Oracle system will refuse to write data to the NFS (default protocol) or CIFS share on the Unitrends system, indicating that it is unable to create the file (manual testing of individual script items indicate that the filesystem is read only, when it is tested and confirmed manually not to be).
Due to the way we perform our RMAN backups, these configuration options are invalid for use with the Unitrends system. The valid options are “asynch” and “none”.
Additional Reading:
https://community.oracle.com/thread/2475652
http://oracle-base.com/articles/misc/direct-and-asynchronous-io.php
Tested and confirmed on RHEL Oracle 11.2.02
For more detailed information on backup failures and performance issues see Unitrends KB 5062 - Backup Failures and Performance Issues