About virtual names and NetBackup for Oracle
Users of a RAC can typically access the database by a virtual network host name. This access is dependent on the configuration of a RAC and any cluster software on which it is running.
The virtual network host name may be associated with an IP address in the following ways:
With an IP address for a host in the cluster
A virtual IP address for an Oracle database instance running on a host in the cluster
A failover virtual IP address that may move between the hosts in the cluster
Backup operations may use the various virtual network host names, or the network host name of the hosts in the cluster.
To differentiate between the various network names, the following terms and definitions are used:
Host name | The network host name that is associated with a specific host in the cluster. |
VIP name | The network host name that is associated with a virtual IP address specific to an instance in the cluster. |
Failover name | The network host name that is associated with an IP address that is active on a running node. This network host name is the network host name that can perform a backup at this time. |
Warning:
Do not use a single client name if the backup is load balanced across more than one node. In a load-balanced configuration, the node that hosts the IP address to which the client name resolves, generates successful backups. However, the jobs originating from the other nodes fail with status code 54.
Oracle 11g R2 Grid Infrastructure (CRS) includes the Single Client Access Name (SCAN) feature. A single SCAN can resolve to multiple IP addresses each assigned to a different physical node in the cluster.
A SCAN can be used in a NetBackup policy that receives the Application Backup request. However, this abstraction of the client name causes backup and restore jobs to fail with status code 54. Also, the client side fails with status code 6 (backup) or status code 5 (restore).
Accordingly, ensure that the client that appears in the NetBackup Oracle policy is not a SCAN. Also, ensure that any NB_ORA_CLIENT or CLIENT_NAME that the node provides in the backup request is not a SCAN. These names must reliably resolve on both the master server and the media server to an IP address. This IP address allows the server processes to connect to the node from which the backup request originated.