# Parameters in /vsmserver/

In this section, we will describe all the parameters used by the master service (`vsmserver.service`). These configuration parameters reside in `/opt/thinlinc/etc/conf.d/vsmserver.hconf`.

/vsmserver/admin_email

  The administrators’ email addresses. This is where warnings about overuse of Licenses are sent, among with other administrative messages.

  `admin_email` is a space-separated list of email addresses, that needs to contain at least one email address. Make sure that all listed email addresses are valid.

/vsmserver/allowed_clients

  A space-separated list of hosts from which privileged operations are allowed. The default (empty) allows localhost to do this. Privileged operations are for example to deactivate a session, something that should be allowed by the host running the ThinLinc Web Administration service.

/vsmserver/allowed_groups

  ThinLinc access can be limited to certain groups. If the `allowed_groups` space-separated list is empty, all users are accepted. Otherwise, the user must be a member of the groups listed below, to be able to use ThinLinc. Example:

      allowed_groups = students teachers

/vsmserver/listen_port

  The TCP port the master service listens to for incoming requests. This should normally be set to the same value as `/vsm/vsm_server_port`.

/vsmserver/max_sessions_per_user

  The maximum number of sessions allowed per user. `0` means no limit. The master will attempt to keep all sessions for a user on the same agent server in order to avoid problems. The problems usually come from applications that incorrectly assumes unrivaled access to the user’s home directory. When on the same machine the conditions allow the applications to handle things better.

/vsmserver/unbind_ports_at_login

  If this parameter is true, processes occupying the users’ interval of forwarded ports will be killed at login. This means that if a user logs in twice to the same session, the second login will get working tunnel ports, if this parameter is true. The first session’s tunnel ports will stop working. If the parameter is false, the first session will keep the ports.