Chapter 13. Performance 299
13.1.3  System management
For effective system management, set the appropriate value for ARS_NUM_DBSRVR and create 
the correct file systems for various Content Manager OnDemand components.
ARS_NUM_DBSRVR
The ARS_NUM_DBSRVR parameter is set in the ars.cfg file. This parameter is the maximum 
number of threads that are concurrently open between the Content Manager OnDemand 
library server and DB2. Typically, this value is set to a number between 4 - 30. This number 
must be large enough to support all of the concurrent database requests from all users and 
clients and Content Manager OnDemand commands and daemons, such as ARSLOAD, ARSDOC, 
ARSDB, ARSMAINT, and ARSADMIN. This number must not exceed the number of DB2 batch 
connections (MAXDBATS for z/OS and MAXAPPLS for Multiprocessing (MP)). The number of DB2 
batch connections must be greater than the ARS_NUM_DBSRVR, plus all of the other connections 
that are required by all DB2 applications that you defined in your DB2 configuration. 
For systems that are running several large load jobs in parallel, or for systems with large 
numbers of active users, increase this parameter from the default of 4.
File systems on UNIX
During the installation and setup of Content Manager OnDemand, one of the tasks is to 
create the file systems that are required to contain the various Content Manager OnDemand 
components. 
For performance reasons, when the Content Manager OnDemand file systems are created, 
the following components must not be on the same physical media:
/SM590000Cache file system
/SM590000Database file system
/SM590000Primary logs file system
/SM590000Secondary logs file system
/SM590000Load/indexing file system
/SM590000Content Manager OnDemand temporary space file system
13.1.4  Storage management
Regardless of the platforms, storage management with Content Manager OnDemand can be 
divided into two areas: cache storage that is managed by Content Manager OnDemand and 
archive media that is managed by an external product, such as IBM Tivoli Storage Manager, 
object access method (OAM), Virtual Storage Access Method (VSAM), or Archive Storage 
Manager (ASM). 
For effective storage management, one key performance feature of Content Manager 
OnDemand is its ability to load data to archive media, while simultaneously retaining a 
temporary cached copy of the most recent archived data on fast access media (such as the 
hard disk drive (HDD)). Content Manager OnDemand handles the expiration and 
management of this cached copy of the data. After a certain predefined period elapses, the 
data is removed from cache. The only remaining copy is held on the much slower archive 
media that is managed by either Tivoli Storage Manager, OAM, VSAM, or ASM, depending on 
the platform. 
If performance problems are encountered at the storage manager level, the issue is almost 
always related to the inherent qualities of the slower media types (such as optical platters and 
tape volumes) or how the archive media manager is configured.