Chapter 12. Scalability, reliability, and availability architectures 289
This example and all of the following examples, from an external perspective, show a single 
Content Manager OnDemand instance. The fact that the system consists of multiple 
distributed systems is transparent to both of the following groups:
/SM590000The Content Manager OnDemand administrator, who continues to administer the system 
through the Content Manager OnDemand Administrator Client as though it is a single 
physical system.
/SM590000The Content Manager OnDemand users, who continue to access the whole system 
through a single IP address (that of the library server) and see only a single system from 
their perspective.
12.2.4  Horizontal and vertical scalability: Storage manager
This form of horizontal scalability provides better performance, reliability, and scalability by 
distributing the storage and retrieval workload over multiple storage subsystems within each 
object server. 
An object server controls the storage and retrieval of the archived data. The archived data is 
stored in a storage subsystem. The number and architecture of these subsystems can be 
scaled to the limitations of the subsystem. Each object server can support one or more 
storage subsystems, and each storage subsystem can consist of multiple storage devices, as 
shown in Figure 12-3.
Figure 12-3   Horizontal and vertical scaling: Multiple storage managers
Archive  sc alability
Li b rary
Server
Object
Server
Ob ject
Server
+
On De m an d In s tan ce
Adm i nis tra tor
Use rs (Gui Clie nt, We b Client, APIs… )
Lo ad 
Process
Lo ad
Process
+
Storage subsystems
Ca che, OAM, TSM