Two main backup environment topologies are as follows: 

GLYPH<SM590000> Single domain backup environment 

A single domain backup environment shares a catalog across the primary and DR sites. Its entries are visible for both servers always. In a single domain environment, the backup application is fully aware of the whereabouts and status of the cloned cartridges. 

Note:  The single domain backup environment works well with Symantec NetBackup, but does not work with Tivoli Storage Manager. 

GLYPH<SM590000> Multiple domain backup environment 

A multiple domain environment requires the user to recover the DR backup server by using a copy of the catalog or DB that matches the replicated repository cartridges that are set before restoring their replicated data from the ProtecTIER system at the DR site. 

## 12.7 Remote cloning of virtual tapes 

Remote cloning is the process of using a secondary (DR) site to clone cartridges. You can use ProtecTIER replication to offload tape cloning to your secondary site. Many users replicate their data from the primary site to the secondary (DR) site, and then move it from the disk-based repository on to physical tape cartridges for long-term retention. 

One of the advantages of this practice at the secondary site is that it shifts the burden of cloning to physical tape from the production environment to the DR site location. The DR site cloning operation uses the cartridge replicas at the ProtecTIER VTL shelf of the destination. The process imitates the commonly used physical process for the transportation of physical cartridges from the primary site to a DR site. 

This feature is effective in single domain backup deployments because in these environments the backup application servers at both sites share the catalog and can be concurrently connected to the ProtecTIER systems. The replication visibility switch control feature is used in these environments. The cartridges to be cloned are moved from the primary repository to the secondary repository and then cloned to physical tapes. 

