Standing up a new environment, with NBU 9.1 on Linux media servers, writing to Data Domains across 2 data centers, using SLPs. One thing that I am still unclear on after reading the "Selection of storage units: performance considerations" section of the Planning and Tuning Guide, is should I have 1 STU per media server, and put those STUs in a SUG? Or have 1 STU, and allow only specific media servers to write to it ?
For example, if I have 3 media servers at each DC, and 1 DD at each DD, should I create 3 STUs (1 per media server) and put those in a SUG so that backups are spread across the 3 media servers? Or, create 1 STU and select the 3 media servers in the "Only use these media servers" selection? I assume that would also spread the backups across the 3 media servers.
I would go with creating 3 storage units and create a storage group. You have flexibility to manage backups and control sending backups to a particular media sever without any changes to a storage unit. You will be able to control backups that can go to specific media server if a need arise. Its easy to check performance if you encounter any by isolating a particular media server storage unit from the backups.
Either way you will be able to control most of the backup configuration.