Operating system command failed

Backup directory does not exist.

...
INFO | jvm 1 | 2013/05/21 09:36:47 | Process timed out: false
INFO | jvm 1 | 2013/05/21 09:36:47 | Process exception null
INFO | jvm 1 | 2013/05/21 09:36:47 | Process stderr: Error: »
    The directory '/opt/continuent/backups/xtrabackup' is not writeable
...

Backup Retention