Choosing a Site Hierarchy
One of the first decisions you make when planning your SMS site design is the general type of site hierarchy that will work best for your organization. Depending on the business needs and physical layout of your organization, your hierarchy will be either flat and wide with many site servers and fewer clients, or steep and narrow with fewer site servers and many clients.
When deciding which type of hierarchy will best suit your organization, consider these questions:
- What is the help desk model of your organization?
- If you will use a central help desk for your entire hierarchy, you will want your help desk personnel to use the central site server to access resource information for the entire organization, and the distribution of sites below it in your narrow hierarchy may not matter very much. However, if you have multiple help desks, each responsible for different departments within your organization, you might want to distribute the work load for help desk personnel and make security easier to maintain by having a greater number of sites that perform help desk operations. In a wider hierarchy such as this, clients can report to sites that service their particular department.
- How much do you need to limit the impact of possible site failures?
- In a steeper hierarchy, if a site server goes down but it has multiple child sites below it, you lose the ability to manage all the clients that are in that part of the hierarchy while you rebuild that site server. However, in a flatter hierarchy, the sites will be more spread out and losing a single site server may have less impact to the hierarchy as a whole.
- What response times do you need your sites to have?
- Every layer of sites in the hierarchy increases the length of time it takes for configuration changes to travel up and down the hierarchy.
- What is your hardware budget?
- The steeper your hierarchy, the more it will cost you in equipment because each layer of sites in the hierarchy will need to process all the objects of the sites below it. If you continue to add clients at each level in the hierarchy, each set of site servers will need progressively more processing power than the level below it.
- How much activity do you expect to travel between sites?
- For example, larger numbers of advertised programs or frequent hardware and software inventory intervals can increase the network traffic between the sites in your hierarchy. This traffic will impact the network links that link the sites in your hierarchy. If you spread out the load more evenly across multiple sites, you may be able to reduce the network load on your WAN.
- What kind of WAN links are involved in your sites?
- If your organization has sites that will be very spread out geographically, carefully consider the costs associated with any WAN links that may exist between SMS sites. Obviously, reducing the number of sites that need to communicate over expensive WAN connections will affect the long-term cost of maintaining your sites.
Except for the central site, which must be a primary site, you also need to decide whether each site will be a primary or a secondary site. If a site will have other sites reporting to it, it must be a primary site. If not, and the site does not require its own SMS site database or local administration, the site can be a secondary site.
While there could be many combinations that would be satisfactory for your organization, be sure to use the pilot project phase to test your site hierarchy design.
For more information about site hierarchy design, see Chapter 3, “Planning for SMS in Your Organization,” in the SMS 2.0 Administrator’s Guide.
After you decide the general type of SMS hierarchy you will need, consider more specifically the number and types of computers to include in the site structure. To do so, determine which SMS features your organization will use.