Managing Users

When you first install XenServer, a user account is added to XenServer automatically. This account is the local super user (LSU), or root, which the XenServer system authenticates locally. You can create extra users by adding Active Directory accounts from the Users tab in XenCenter.


The term “user” refers to anybody with a XenServer account, that is, anyone administering XenServer hosts, regardless of the 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 feature allows XenServer users to log in to the servers in a pool using their Windows domain credentials.


Mixed-authentication pools are not supported. That is, you cannot have a pool where some servers in the pool use Active Directory and some don’t.

When you create a user in XenServer you must first assign a role to the newly created user before they can use the account. XenServer does not automatically assign a role to the newly created user. As a result, these accounts do not have any access to the XenServer 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 XenServer environment

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


You can enable LDAP channel binding and LDAP signing on your AD domain controllers. For more information, see Microsoft Security Advisory.

When added to XenServer, Active Directory users and groups become XenServer subjects, called users in XenCenter. When a subject is registered with XenServer, users and groups are authenticated with Active Directory on login. These users and groups 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.


By default, if you don’t qualify the user name, XenCenter attempts to log users in to Active Directory authentication servers using the domain to which it is joined. The exception to this rule is the LSU account, which XenCenter always authenticates locally (that is, on XenServer) 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 XenServer, 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.

Managing Users