About the treatment of images without a corresponding duplication rule
In some cases, the profile may list more media servers in the list on the Choose Backups tab than in the advanced configuration view on the Duplication tab.
Figure: Media servers listed on Choose Backup and Duplication tabs shows that the number of media servers that appear in the Choose Backup tab can differ from the number of media servers that appear in the Duplication tab.
Note:
More than one media server applies to NetBackup Enterprise Server only.
If this happens, images that are written by media servers that have no corresponding duplication rule must also be duplicated. Vault duplicates those images but tries to minimize total duplication time by keeping as many drives as possible busy writing data until all images are duplicated.
This situation is handled as follows:
All images that are written by media servers that have a duplication rule are assigned to the appropriate duplication rule.
As soon as one duplication rule finishes processing the images that are assigned to it, Vault begins to assign images written by other media servers (media servers that have no rule of their own) to the duplication rule that finished processing.
As other rules complete the duplication of their assigned images, they too are assigned images written by other media servers that have no rule of their own.
Eventually all images that are written by all media servers that are listed on the Choose Backups tab are duplicated and the duplication step is complete. If you have more media servers listed on the Choose Backups tab than on the Duplication tab, there is only one way to ensure that large amounts of duplication data do not get sent over the network.
Every duplication rule must specify an alternate read server. For each duplication rule, the alternate read server must be the same as the media server of the destination storage unit(s).
All alternate read servers must be connected to all robots that have images written by any media server listed on the Choose Backups tab but not on the Duplication tab.
The previous configurations are best suited for a SAN environment where all media servers are visible to all robots.