Determining the Number and Placement of ISA ServersISA Server sizing concepts are not particularly complex, but often depend on the role that ISA will fill in an environment. In general, most organizations rarely tax the processor and memory utilization on an ISA server on updated server hardware, assuming that the server is used primarily for Internet-related traffic, such as web publishing or mail publishing rules. When an ISA server starts to be used for content caching, on the other hand, knowing the number of clients that will access the system becomes very important.
Sizing an ISA Server DeploymentAlthough there are no hard and fast guidelines for ISA Server 2004 sizing, some general suggested hardware minimums, shown in Table 4.2, should be followed when deploying an ISA server.
|To 50 Users||50-500 Users||500+ Users|
|Processor||Single 550MHz Pentium III or equivalent||Single 1GHz Pentium III/IV or equivalen||Single 2GHz Pentium III/IV or equivalent (or greater)|
|Memory||256MB of memory||512MB of memory||1GB of memory (or greater)|
|Disk Space||150MB available (for installation of ISA software), plus space for logs and caching||150MB available (for installation of ISA software), plus space for logs and caching||8GB OS partition 10GB logs partition Additional 18GB+ partition for caching (if necessary)|