Managing Users

When you first install Citrix Hypervisor, a user account is added to Citrix Hypervisor automatically. This account is the local super user (LSU) , or root , which is authenticated locally by your Citrix Hypervisor computer. You can create additional users by adding Active Directory accounts from the Users tab in XenCenter. (Note that the term “user” refers to anybody with Citrix Hypervisor account, that is, anyone administering Citrix Hypervisor hosts, regardless of level of their role.) If you want to have multiple user accounts on a server or a pool, you must use Active Directory user accounts for authentication. This allows Citrix Hypervisor users to log in to the servers in a pool using their Windows domain credentials.

Note: Mixed-authentication pools are not supported (that is, you cannot have a pool where some servers in the pool are configured to use Active Directory and some are not).

When you create a new user in Citrix Hypervisor you must first assign a role to the newly created user before they can use the account. Note that Citrix Hypervisor does not automatically assign a role to the newly created user. As a result, these accounts will not have any access to Citrix Hypervisor pool until you assign them a role.

Using the Role Based Access Control (RBAC) feature, you can assign the Active Directory accounts different levels of permissions depending on the user’s role. If you do not use Active Directory in your environment, you are limited to the LSU account.

AD authentication in Citrix Hypervisor environment

Even though Citrix Hypervisor servers are Linux-based, Citrix Hypervisor lets you use Active Directory accounts for Citrix Hypervisor user accounts. To do so, it passes Active Directory credentials to the Active Directory domain controller.

When added to Citrix Hypervisor, Active Directory users and groups become Citrix Hypervisor subjects , generally referred to as simply users in XenCenter. When a subject is registered with Citrix Hypervisor, users/groups are authenticated with Active Directory on login and do not need to qualify their user name with a domain name.

To qualify a user name, you must enter the user name in Down-Level Logon Name format, for example, mydomain\myuser .

Note: By default, if you did not qualify the user name, XenCenter always attempts to log users in to Active Directory authentication servers using the domain to which it is currently joined. The exception to this is the LSU account, which XenCenter always authenticates locally (that is, on Citrix Hypervisor) first.

The external authentication process works as follows:

  1. The credentials supplied when connecting to a server are passed to the Active Directory domain controller for authentication.
  2. The domain controller checks the credentials. If they are invalid, the authentication fails immediately.
  3. If the credentials are valid, the Active Directory controller is queried to get the subject identifier and group membership associated with the credentials.
  4. If the subject identifier matches the one stored in Citrix Hypervisor, the authentication is completed successfully.

When you join a domain, you enable Active Directory authentication for the pool. However, when a pool is joined to a domain, only users in that domain (or a domain with which it has trust relationships) can connect to the pool.