We currently have a single LMS 2.6 server running all applications and integrated with ACS. The deployment guide says multi-server setup is supported in LMS 2.6, but I cannot find a good link that gives more info.
Can someone please point me in the right direction related to best practices and license requirement for multi-server in ACS integrated environment?
See http://www.cisco.com/en/US/products/sw/cscowork/ps2425/prod_white_papers_list.html for our LMS white papers. The large scale deployment paper will be of particular interest. It's for LMS 3.0, but the concepts still apply to LMS 2.6.
In general, you will need to purchase a license for each LMS server unless you plan on separating the bundle. That is, if no application is duplicated on each server, you only have to use one license. If, however, you install the same application on two different servers, then you will need a separate license for each server. Note: Common Services does not count. You can install as many copies of Common Services as you want.
Another leading practice is to integrate each server with DCR master/slave as well as Single Sign On master/slave. This way, there is one device and credentials list that gets replicated across all servers. Additionally, you only need to authenticate against one server, then you will be able to transparently move to each server without entering your username/password again.
Since ACS is in the picture, you will also need to integrate each server with the same ACS server/cluster. While SSO takes care of centralized authentication, it does not synchronize users across all LMS servers. Therefore, you will still need the ACS integration on all servers to handle authorization.