290 IBM Content Manager OnDemand Guide
Each object server can have multiple storage subsystems of different types:
/SM590000Cache: The cache storage subsystem is controlled directly by the object server. Data is 
written to and read directly from cache. Cache consists of one or more cache file systems. 
Each cache file system can be mounted on a different device in its own directory. Each 
device can be placed on its own independent I/O interface/channel. Content Manager 
OnDemand does not impose a limit on the number of devices.
/SM590000IBM Tivoli Storage Manager: Tivoli Storage Manager is an archive storage subsystem. 
The Content Manager OnDemand object server sends data to and requests data from 
Tivoli Storage Manager. Each Tivoli Storage Manager server can be installed on its own 
system (for example, an AIX server). The Content Manager OnDemand object server 
allows the connection of multiple Tivoli Storage Manager servers. So, for example, if the 
Content Manager OnDemand object server is an AIX system and the data that is 
managed by that object server is stored in three Tivoli Storage Manager archives (all of 
which are AIX systems), the total processing capacity for that object server is four AIX 
systems. Each of the AIX systems can be configured with as many processors, memory, 
disks, and I/O as needed, up to its architectural limitation. If more capacity is needed, 
more Tivoli Storage Manager servers or object servers can be added.
/SM590000Object access method (OAM): OAM is a z/OS archive storage subsystem only. Only one 
OAM archive exists for each system. Scalability within the archive is achieved by 
increasing the number of storage groups. A z/OS system can grow by increasing the 
number of processors, amount of memory, number of disks, and I/O. If more capacity is 
needed than can be provided by a single system, z/OS allows multiple systems to be 
connected in a Parallel Sysplex. All of these systems then can access the same OAM 
subsystem, therefore providing unparalleled scalability, reliability, availability, and 
performance.
Both Tivoli Storage Manager and OAM provide hierarchical data management facilities. Data 
can be stored on different devices based on the age or predicted frequency of data access. 
For example, frequently accessed data might be placed on high-speed disk and infrequently 
accessed data might be placed on tape. When the data is requested by a user, the location of 
the data is transparent to the user. The only perceived difference from a user perspective is 
the response time, which is mainly a factor of the type of device on which the data is stored. In 
this example, tape access is slower than disk access.
In summary, better performance is achieved by distributing the storage and retrieval workload 
over multiple systems and multiple devices.
12.2.5  Horizontal scalability: Multiple logical partitions and systems 
This scenario is similar to the multiple object server scenario where each object server is 
running on a separate system. In this case, the library server and one or more object servers 
are installed in separate LPARs on one or more physical systems, as shown in Figure 12-4 on 
page 291.