Maico,
1. The SMSP Backup Index LUN is connected to the SMSP Manager server to store the metadata about the SMSP backups. The metadata is also called the backup index data. The backup index data can be created after the backup is created or during an SMSP maintenance job.
The SMSP media server service works with the SMSP member agent to index the clone of the content database (created by SMSQL) to create backup index metadata that is stored on the SMSP backup index LUN.
2. Since you won't be using the SharePoint Search, you can exclude the SharePoint Search database and SharePoint Search Index data from the SMSP backup plan. This also means that you don't need to put the SharePoint Search Index data on a LUN connected to the server that has the SharePoint Search role installed.
3. SMSP has an RBS provider that allows you to store SharePoint content outside of SQL server. The idea behind storing content outside of SQL is that you get better performance and scalability for SharePoint than storing and retrieving the data from SQL. RBS is an MS SQL API only available in SQL 2008R2 Enterprise Edition. The BLOBs can be stored in a LUN or on a CIFS share. Typically, the BLOBs are stored on a CIFS share on SATA disk. The CIFS share or LUN can only be on NetApp storage.
SMSP leverages RBS in two ways: Extender and Archiver. In the SMSP documentation, Extender and Archiver is considered storage optimization.
Extender has policies that can be applied to new or existing content that externalize SharePoint content via RBS based entirely on content size. The scope of an Extender policy is at the web application level. (A web application can have multiple databases, but usually just has one.) Uploaded content is converted into BLOB format by the SMSP provider on the WFE and stored directly into the CIFS share. Retrieved content is retrieved from the CIFS share and then converted back into the original file format.
Archiver is similar to Extender in that it can externalize content based on size, but also based on complex business rules. These rules can be where the content is located, last access time, last modified time, file name, etc. You can create custom Archiver rules as well as using built in rules. You use Archiver to age out content or to store content on NetApp SnapLock enabled volumes for compliance reasons. The value of Archiver is that you age out stale content based on business rules that are based on records retention policies within your company.
Uploaded content is converted into BLOB format by the SMSP provider on the WFE and sent to the SMSP media service for the Archiver rules to be applied. When data is Archived, the SharePoint administrator can set a property on the content denoting that the content has been archived and the document icon can be modifed to show that the content has been archived as well.
One Archived content has expired the BLOB and the stubs are deleted from the farm and are not restorable. It is recommended that you have careful planning and a robust records retention policy prior to implementing Archiver policies.
Thanks,
Mark